Recovery Strategy for the Bicknell’s Thrush (Catharus bicknelli) in Canada - 2016 [Proposed]

Species at Risk Act
Recovery Strategy Series

Bicknell’s Thrush

Photo of Bicknell’s Thrus
Photo: © Yves Aubry, 2016

Table of contents

List of figures

  • Figure 1. Bicknell’s Thrush breeding range in Canada and the United States, in green (adapted from Lambert et al. 2005; Hart et al. in prep.; and unpublished data of Environment and Climate Change Canada’s Canadian Wildlife Service).
  • Figure 2. Potential wintering area of the Bicknell’s Thrush in the Greater Antilles, in green. The black triangles indicate the known observation sites of the species (adapted from McFarland et al. 2013)

List of tables

  • Table 1. Subnational conservation status ranks (S-ranks) for the Bicknell’s Thrush in Canada and the United States (NatureServe 2013)
  • Table 2. Threat assessment table
  • Table 3. Recovery planning table
  • Table 4. Schedule of studies to identify critical habitat
  • Table 5. Examples of activities likely to result in the destruction of critical habitat

Document Information

Recovery Strategy for the Bicknell’s Thrush (Catharus bicknelli) in Canada - 2016 [Proposed]

Photo of cover

Recommended citation:

Environment and Climate Change Canada. 2016. Recovery Strategy for the Bicknell’s Thrush (Catharus bicknelli) in Canada [Proposed], Species at Risk Recovery Strategy Series, Environment and Climate Change Canada, Ottawa, viii + 72 pp.

For copies of the recovery strategy, or for additional information on species at risk, including COSEWIC Status Reports, residence descriptions, action plans, and other related recovery documents, please visit the Species at Risk Public Registry.

Cover illustration: Yves Aubry ©

Également disponible en français sous le titre
« Programme de rétablissement de la Grive de Bicknell (Catharus bicknelli) au Canada [Proposition] »

Content (excluding the illustrations) may be used without permission, with appropriate credit to the source.

Preface

The federal, provincial, and territorial government signatories under the Accord for the Protection of Species at Risk agreed to establish complementary legislation and programs that provide for effective protection of species at risk throughout Canada. Under the Species at Risk Act (S.C. 2002, c. 29) (SARA), the federal competent ministers are responsible for the preparation of recovery strategies for listed Extirpated, Endangered, and Threatened species and are required to report on progress within five years after the publication of the final document on the SAR Public Registry.

The Minister of Environment and Climate Change and Minister responsible for the Parks Canada Agency is the competent minister under SARA for the Bicknell’s Thrush and has prepared this recovery strategy, as per section 37 of SARA. To the extent possible, it has been prepared in cooperation with the Quebec Department of Forests, Wildlife and Parks, the New Brunswick Department of Natural Resources, and the Nova Scotia Department of Natural Resources, as per section 39(1) of SARA.

Success in the recovery of this species depends on the commitment and cooperation of many different constituencies that will be involved in implementing the directions set out in this strategy and will not be achieved by Environment and Climate Change Canada, the Parks Canada Agency, or any other jurisdiction alone. All Canadians are invited to join in supporting and implementing this strategy for the benefit of the Bicknell’s Thrush and Canadian society as a whole.

This recovery strategy will be followed by one or more action plans that will provide information on recovery measures to be taken by Environment and Climate Change Canada, the Parks Canada Agency and other jurisdictions and/or organizations involved in the conservation of the species. Implementation of this strategy is subject to appropriations, priorities and budgetary constraints of the participating jurisdictions and organizations.

The recovery strategy sets the strategic direction to arrest or reverse the decline of the species, including identification of critical habitat to the extent possible. It provides all Canadians with information to help take action on species conservation. When critical habitat is identified, either in a recovery strategy or an action plan, there may be future regulatory implications, depending on where the critical habitat is identified. SARA requires that critical habitat identified within a national park named and described in Schedule 1 to the Canada National Parks Act, the Rouge National Urban Park established by the Rouge National Urban Park Act, a marine protected area under the Oceans Act, a migratory bird sanctuary under the Migratory Birds Convention Act, 1994 or a national wildlife area under the Canada Wildlife Act be described in the Canada Gazette, after which prohibitions against its destruction will apply. For critical habitat located on other federal lands, the competent minister must either make a statement on existing legal protection or make an order so that the prohibition against destruction of critical habitat applies. For any part of critical habitat located on non-federal lands, if the competent minister forms the opinion that any portion of critical habitat is not protected by provisions in or measures under SARA or other Acts of Parliament, or the laws of the province or territory, SARA requires that the Minister recommend that the Governor in Council make an order to prohibit destruction of critical habitat. The discretion to protect critical habitat on non-federal lands that is not otherwise protected rests with the Governor in Council.

Acknowledgements

This recovery strategy was prepared by François Shaffer (Environment and Climate Change Canada, Canadian Wildlife Service – Quebec Region), based on a draft by Benoît Audet (private consultant). This document was made possible through the contributions of Yves Aubry, Bruno Drolet, Sébastien Paradis, Karine Picard, Josée Tardif, Charles Clavet, Geneviève Langlois and Vincent Carignan (Environment and Climate Change Canada, Canadian Wildlife Service – Quebec Region), Andrew Boyne, Becky Whittam, Peter Thomas and Samara Eaton (Environment and Climate Change Canada, Canadian Wildlife Service – Atlantic Region), James Bridgland, Mathieu Côté, Edouard Daigle, Jean-Louis Provencher, Darroch Whitaker (Parks Canada Agency), Isabelle Gauthier and Jérôme Lemaître (Quebec Department of Forests, Wildlife and Parks), Scott Makepeace, Steve Gordon, Hubert Askanas and Maureen Toner (New Brunswick Department of Natural Resources), Mark Elderkin (Nova Scotia Department of Natural Resources), Manon Dubé (Environment and Climate Change Canada, Canadian Wildlife Service – National Capital Region) and Marie-José Ribeyron (private consultant).

Executive summary

The Bicknell’s Thrush (Catharus bicknelli) was listed as a threatened species in Schedule 1 of the Species at Risk Act (SARA) in 2012.

The Bicknell’s Thrush is a rare, range-restricted passerine species. During the breeding season, the species inhabits inland forests at elevations ranging from 380 to 1,100 m, as well as coastal lowland forests in Quebec, New Brunswick, Nova Scotia and the northeastern United States. It winters in the Greater Antilles, with the bulk of its population occurring in the Dominican Republic (Hispaniola). All the available indices on population trends for the species in Canada indicate a decline in abundance and range.

The main threat facing the Bicknell’s Thrush is habitat loss and degradation. The wintering area is particularly subject to pressures such as subsistence farming, logging and human-caused fires. In the breeding range, Bicknell’s Thrush habitats are mainly affected by forestry practices as well as the creation of wind farms.

There are unknowns regarding the feasibility of recovery of the Bicknell’s Thrush. Nevertheless, in keeping with the precautionary principle, this recovery strategy has been prepared as per section 41(1) of SARA, as is done when recovery is determined to be feasible.

The population and distribution objectives for the Bicknell’s Thrush are as follows:

  • in the short term (2016-2026), slow the decline in its population while ensuring that no more than 10% of the population is lost during this period, and ensure that no net loss occurs in its biological area of occupancyFootnote 1 throughout the species’ entire range in Canada;
  • in the long term (after 2026), ensure a positive population trend over 10 years, as well as a positive trend in the species’ biological area of occupancy, throughout the species’ range in Canada.

The broad strategies to be taken to address the threats to the survival and recovery of the species are presented in the section on Strategic Direction for Recovery.

The Bicknell’s Thrush critical habitat is partially identified in this recovery strategy. The identification of critical habitat is based on two criteria: the presence of suitable habitat for the Bicknell’s Thrush and occupancy of this habitat by the species. It corresponds to suitable habitat within a radius of 5 km of all coordinates representing a possible, probable or confirmed breeding record obtained over the period from 1995 to 2014. A schedule of studies outlines the key activities that are required to complete the identification of critical habitat. Examples of activities likely to result in the destruction of critical habitat are also outlined.

One or more action plans for the Bicknell’s Thrush will be posted on the Species at Risk Public Registry within five years after the final version of this recovery strategy is posted.

Recovery feasibility summary

Based on the following four criteria that Environment and Climate Change Canada uses to establish recovery feasibility, there are unknowns regarding the feasibility of recovery of the Bicknell’s Thrush. In keeping with the precautionary principle, this recovery strategy has been prepared as per subsection 41(1) of SARA, as would be done when recovery is determined to be technically and biologically feasible. This recovery strategy addresses the unknowns surrounding the feasibility of recovery.

1. Individuals of the wildlife species that are capable of reproduction are available now or in the foreseeable future to sustain the population or improve its abundance.

Yes. The Bicknell’s Thrush population has a significant number of wild breeding individuals. According to the most recent status report, the global population is between 98,050 and 125,898 individuals and the Canadian population is between 40 570 and 49 258 (COSEWIC 2009). This number of individuals is sufficient to sustain and increase the population.

2. Sufficient suitable habitat is available to support the species or could be made available through habitat management or restoration.

Unknown. The potential breeding habitat for the species in Canada is an estimated 48,850 km2 (COSEWIC 2009). A large part of this area is located in managedFootnote 2 forests, and the size of the area therefore depends on how the forests are managed and on the nature of the forest treatments. Certain types of activities carried out in forests, such as the construction of access roads and wind farm developments, can permanently reduce the area of suitable habitat. The availability of wintering habitat (located in the Greater Antilles) is considered an important limiting factor for the species. Its total current area has been assessed at ±33 170 km2 (McFarland et al. 2013) and will likely continue to decrease given the major challenge of reducing the threats to the species’ habitat owing to the difficult socio-economic situation in the Dominican Republic and Haiti (Stattersfield et al. 1998; Perdomo and Arias 2008; Sergile 2008) and given the fact that less than 30% of the potential habitat identified has conservation status (McFarland et al. 2013). Efforts to manage or restore the species’ wintering habitat could improve the situation, but it is not certain that such efforts would succeed in reversing this trend and increasing the area of wintering habitat.

3. The primary threats to the species or its habitat (including threats outside Canada) can be avoided or mitigated.

Unknown. The primary threats to the Bicknell’s Thrush and its habitat in its breeding range can be avoided or mitigated through legal measures or other methods such as stewardship or appropriate management approaches. The threats relating to climate change, if confirmed, pose a challenge, but it is reasonable to believe that avoidance or mitigation of other threats, some of which have greater impacts, will make it possible to improve the environmental and ecological conditions to the point of enabling the species to recover. The likelihood of success in avoiding or mitigating the threats present in the species’ wintering area, in particular threats to its habitat, is however more uncertain for the reasons noted in criterion 2.

4. Recovery techniques exist to achieve the population and distribution objectives or can be expected to be developed within a reasonable timeframe.

Yes. Forest management techniques and measures for managing habitat used by the Bicknell’s Thrush exist which, taken together, can maintain or promote the regeneration of breeding habitat. In the wintering area, different habitat creation or conservation techniques will have to be developed or adapted.

1 COSEWICi species assessment information

Date of assessment:
November 2009
Common name (population):
Bicknell’s Thrush
Scientific name:
Catharus bicknelli
COSEWIC status:
Threatened
Reason for designation:
This species has one of the most restricted breeding ranges among the forest birds of North America. It inhabits the forests of montane and cool coastal zones, as well as high-elevation regenerating forests over 600ii m in Quebec, New Brunswick, Nova Scotia and the northeastern United States. It winters in the Greater Antilles, where the bulk of its population appears to be in the Dominican Republic. Despite the difficulty of adequately monitoring the species, all the available indices on trends point to significant declines in population and area of occupancy. Preliminary results from the Maritimes Breeding Bird Atlas project suggest a 40% decline in the area occupied over the last three generations, while the High Elevation Landbird Program suggests more dramatic declines in the same regions. Recent surveys in Quebec also indicate declines in some locations. While reasons for the decline are unclear, habitat loss on the wintering grounds, management practices such as pre-commercial thinning in regenerating forests and climate change are leading to a reduction of suitable high-elevation habitat.
Canadian occurrence:
Quebec, New Brunswick, Nova Scotia
COSEWIC status history:
Designated Special Concern in April 1999. Status re examined and designated Threatened in November 2009.

i COSEWIC (Committee on the Status of Endangered Wildlife in Canada)

ii New information that has become available since the publication of the COSEWIC status report on the Bicknell’s Thrush indicates that the species occurs in forests ranging in elevation from 380 m to 1,100 m (IBTCG 2010).

2 Species status information

Approximately 95% of the Bicknell’s Thrush potential breeding habitat is in Canada (COSEWIC 2009). The Bicknell’s Thrush was listed as Threatened in Schedule 1 of the Species at Risk Act in 2012. It is designated Vulnerable in Quebec under the Act Respecting Threatened or Vulnerable Species(CQLR, c. E-12.01), Vulnerable in Nova Scotia under the Endangered Species Act (c. 11, s. 1.) and Threatened in New Brunswick under the Species at Risk Act (Regulation 2013-38). It is listed as a Species of Concern in all the U.S. states in which it occurs.

The Bicknell’s Thrush is considered to be “apparently secure globally” (G4) (NatureServe 2013) and has national breeding status ranks of N4B (apparently secure) in Canada and N3B (vulnerable) in the United States. The subnational conservation status ranks for the species vary by state or province (see Table 1).

Table 1. Subnational Conservation Status Ranks (S-ranks) for the Bicknell’s Thrush in Canada and the United States (NatureServe 2013)
CountryProvinces/States and NatureServe conservation status ranksa
CanadaNew Brunswick (S2S3B), Nova Scotia (S1S2B), Ontario (SNA), Prince Edward Island (SUB), Quebec (S2b)
United StatesConnecticut (SNA), Delaware (SNA), Georgia (SNA), Maine (S3B), Maryland (SNA), Massachusetts (SXB), New Hampshire (S2S3B), New Jersey (SNA), New York (S2S3B), North Carolina (SNA), Pennsylvania (SNA), Rhode Island (SNA), South Carolina (SNA), Vermont (S2B), Virginia (SNA)

a See Appendix A for definitions of the status ranks used by NatureServe (2013).

b Source: Centre de données sur le patrimoine naturel du Québec (2015).

3 Species information

3.1 Species description

Discovered in 1882 but only recognized as a distinct species since 1995, the Bicknell’s Thrush is the smallest of the northern Catharus thrushes (body length: 16–18 cm; body mass: 25–30 g). Its upperparts are mainly drab olive brown and the underparts are gray with dark spots on the throat and breast. The folded primaries and rump (upper tail) feathers are chestnut brown. During the breeding season, its lower mandible is pale yellow on at least the proximal half. There is no obvious sexual dimorphism, but males can be slightly larger than females (Frey et al. 2008). The Bicknell’s Thrush is similar to the other northern Catharus thrushes, particularly the larger Gray-cheeked Thrush (COSEWIC 2009).

3.2 Population and distribution

The Bicknell’s Thrush has a restricted range. Its breeding range lies entirely within the northeastern part of the North American continent (Figure 1). In Canada, the Bicknell’s Thrush nests in southern Quebec, in north-central and northwestern New Brunswick and on Cape Breton Island in Nova Scotia. The breeding range is fragmented owing to the specific conditions sought by this species (e.g., high elevation, specific forest stands; see section 3.3 for more information). The species’ wintering area is equally restricted and located in the Greater Antilles, primarily the Dominican Republic (Hispaniola Island) (Figure 2; IBTCG 2010; McFarland et al. 2013).

Figure 1. Bicknell’s Thrush breeding range in Canada and the United States, in green (adapted from Lambert et al. 2005; Hart et al. in prep.; and unpublished data of Environment and Climate Change Canada’s Canadian Wildlife Service).
Map of Bicknell’s Thrush breeding range (see long description below)
Long description for Figure 1

Figure 1 depicts the distribution of the breeding range for Bicknell’s Thrush which lies throughout the northeastern part of North America. The main focus is in Canada with nests in southern Quebec, north-central and northwestern New Brunswick and on Cape Breton Island in Nova Scotia. There is little distribution in Maine.

Figure 2. Potential wintering area of the Bicknell’s Thrush in the Greater Antilles, in green. The black triangles indicate the known observation sites of the species (adapted from McFarland et al. 2013)
Map of potential wintering area (see long description below)
Long description for Figure 2

Figure 2 depicts the distribution of the potential wintering area of the Bicknell’s Thrush in the Greater Antilles as well as the known observation sites of the species. The main focus of the potential wintering areas and the observation sites are found in the Dominican Republic (Hispaniola Island) with some concentration of potential wintering throughout Jamaica, Puerto Rico and a few in the southern region of Cuba. A couple known observation sites can be found in these areas as well.

The species has a small global population (estimated at 98 050 to 125 898 individuals), of which 40 570 to 49 258 individuals breed in Canada (COSEWIC 2009). Given this species’ skewed sex ratio, there would be only 10 142 to 16 419 females. This represents the maximum reproductive population size for the species in Canada (COSEWIC 2009).

Population trends for the Bicknell’s Thrush in Canada have declined, regardless of the region and period considered. The data collected through the Breeding Bird Survey program indicate a 3.42% overall annual decline in Bicknell’s Thrush abundance in Canada between 1970 and 2012.Footnote 3 According to data from the same program, the annual decline for Nova Scotia over the same period is 7.07%, which is comparable to the results of the analysis of the data of the High Elevation Landbird Program (HELP) conducted by Campbell and Stewart (2012), which found an abundance decline of approximately 7.4% annually between 2002 and 2011. For New Brunswick, this figure rises to 11.5% over the same period (Campbell and Stewart 2012). For these two provinces combined, Bicknell’s Thrush distribution has reportedly decreased by 65% over approximately 20 years and by more than 40% in the last 10 years (COSEWIC 2009). In Quebec, while a population trend cannot yet be calculated for the species, monitoring carried out at Mount Gosford from 2001 to 2007 reveals a 60% decline in the number of individuals detected (Y. Aubry, Environment and Climate Change Canada, unpublished data reported by IBTCG 2010).

3.3 Needs of the Bicknell’s Thrush

Breeding habitat

The Bicknell’s Thrush is a habitat specialist. It is generally associated with dense undisturbed coniferous forest or disturbed areas undergoing vigorous succession dominated by Balsam Fir (Abies balsamea) with high stem densities (10,000–50,000 stems/ha) (COSEWIC 2009; Bredin and Whittam 2009). Elevation is an important characteristic of the species’ breeding habitat. In Canada, at inland sites in the southern part of the species’ range, the minimum elevation is approximately 800 m. This minimum elevation declines with increasing latitude, to approximately 380 m in the northern limit of its range (IBTCG 2010). In coastal localities, the Bicknell’s Thrush occurs from elevations starting near sea level. Because of these specific requirements, the species’ breeding range is fragmented, which increases its vulnerability of being extirpated from one or more smaller breeding sites (Bredin and Whittam 2009).

Three breeding habitat types are used by the Bicknell’s Thrush (COSEWIC 2009). High Balsam Fir stem density is an important characteristic of all three (Wallace 1939; Sabo 1980; Connolly 2000; Nixon et al. 2001; Whittam and Ball 2003; Frey et al. 2008; Aubry and Paradis 2009; Y. Aubry unpubl. data).

High-elevation montane forests

In high-elevation montane areas, the Bicknell’s Thrush selects undisturbed forests and forests regenerating after natural disturbances (e.g., fir stands affected by fir wave mortality [Sprugel 1976], windthrow, ice and snow damage, fire and insects, such as Spruce Budworm [Choristoneura fumiferana]), with standing dead conifers and dense regrowth of Balsam Fir (Wallace 1939; Rimmer et al. 2001). The species also uses chronically disturbed, stunted-tree stands (Rimmer et al. 2001).

High-elevation managed forests

Managed forests are defined as forests managed for wood or fibre production (COSEWIC 2009). The Bicknell’s Thrush breeds in these anthropogenically disturbed forests, i.e., in regenerating clearcuts and unthinned conifer plantations 10 to 15 years after cutting (Bredin and Whittam 2009), when they have been invaded by dense regeneration of Balsam Fir. Studies conducted in New Brunswick and Nova Scotia indicate that these stands are dominated by Balsam Fir and that the Bicknell’s Thrush uses stands with a stem density as high as 50 000 stems per hectare and an average young tree height of 3.4 m in New Brunswick and 5 m in Nova Scotia (Campbell et al. 2005; Bredin and Whittam 2009).

Coastal lowland forests

Locally, the species also occupies similar habitats in coastal localities, where the maritime climate, cool offshore winds and high precipitation levels maintain dense spruce-fir stands (COSEWIC 2009). This is the case in Nova Scotia where, according to Bredin and Whittam (2009), the species traditionally nests in dense, often stunted coniferous forests typically found on coastal headlands. These forests are composed primarily of Balsam Fir and Black Spruce (Picea mariana) and are sometimes referred to as krummholtzFootnote 4 or taiga.

Post-breeding habitat

Little information is available on post-breeding habitat use by Bicknell’s Thrush. The species may use forest habitat at a lower elevation than the breeding habitat because this habitat provides the conditions and food resources necessary for the species’ survival just ahead of migration (Collins 2007). However, the species has also been found in habitats located at higher elevations prior to migration (Rimmer and McFarland 2000).

Migration habitat

Little is known about habitat selection by the Bicknell’s Thrush during migration. It appears to use a variety of habitats at both coastal and inland localities, which suggests little specificity of habitat use (Rimmer et al. 2001; COSEWIC 2009). Migratory routes for the Bicknell’s Thrush are poorly documented, but appear to be concentrated east of the Appalachian Mountains (Wilson and Watts 1997). Southbound migrants gather north of the Carolinas before an oceanic flight to their wintering grounds. Northbound migrants apparently travel through eastern Florida and northward along the coastal plain (Evans 1994; Rimmer et al. 2001).

Wintering habitat

The forests occupied by the species in its wintering grounds span a series of successional and disturbance regimes, from undisturbed primary forest to moderately disturbed secondary forest (Rimmer et al. 2001). The variables that are the best predictors of wintering habitat use by this species are elevation, land cover (marked preference for broadleaf forests), average winter precipitation, slope and aspect (McFarland et al. 2013).

The available wintering habitat covers only 33 170 km2 in the Greater Antilles, 28.5% of which has protected status of some kind (McFarland et al. 2013). The availability of wintering habitat is considered an important limiting factor for this species. The wintering habitat is subject to serious threats (see section 4).

4 Threats

4.1 Threat assessment

Table 2. Habitat loss or degradation threat assessment table
ThreatLevel of ConcerncExtentOccurrenceFrequencySeveritydCausal Certaintye
Subsistence farming, logging and human-caused fires in the wintering areaHighLocalizedCurrentContinuousHighHigh
Forestry practices in the breeding rangeHighLocalizedCurrentSeasonalHighHigh
Construction of wind farms in the breeding rangeHighLocalizedCurrent NS:AnticipatedContinuousHighHigh
Clearing for recreational development in the breeding rangeMediumLocalizedCurrentContinuousModerate to highHigh
Development for telecommunications in the breeding rangeMediumLocalizedCurrentContinuousModerateHigh
Overgrazing by moose in the breeding range

Low

Medium (Nova Scotia)

LocalizedCurrentContinuousModerate

Low

Medium (Nova Scotia)

Coastal development along flywaysLowLocalizedCurrentContinuousUnknownLow
Table 2. Exotic, invasive or introduced species/genome threat assessment table
ThreatLevel of ConcerncExtentOccurrenceFrequencySeveritydCausal Certaintye
Rats and cats introduced into the wintering areaMediumLocalizedCurrentSeasonalModerateMedium
Table 2. Pollution threat assessment table
ThreatLevel of ConcerncExtentOccurrenceFrequencySeveritydCausal Certaintye
Acid precipitationLowWidespreadCurrentContinuousUnknownMedium
Mercury bioaccumulationLowWidespreadCurrentContinuous LowLow
Lead poisoningLowWidespreadAnticipatedContinuousUnknownLow
Table 2. Accidental mortality threat assessment table
ThreatLevel of ConcerncExtentOccurrenceFrequencySeveritydCausal Certaintye
Collisions with human-made structuresLowLocalizedAnticipatedSeasonalUnknownLow
Table 2. Changes in ecological dynamics or natural processes threat assessment table
ThreatLevel of ConcerncExtentOccurrenceFrequencySeveritydCausal Certaintye
Control over natural disturbancesLowWidespreadCurrentContinuousModerateMedium
Table 2. Natural processes or activities threat assessment table
ThreatLevel of ConcerncExtentOccurrenceFrequencySeveritydCausal Certaintye
Red Squirrel predationLowWidespreadCommonRecurrentModerateLow
Table 2. Disturbance or harm threat assessment table
ThreatLevel of ConcerncExtentOccurrenceFrequencySeveritydCausal Certaintye
Recreational activitiesLowLocalizedAnticipatedSeasonalUnknownLow
Table 2. Climate and natural disasters threat assessment table
ThreatLevel of ConcerncExtentOccurrenceFrequencySeveritydCausal Certaintye
Climate changeUnknownWidespreadAnticipatedContinuousUnknownUnknown

c Level of concern: signifies that managing the threat is of (high, medium or low) concern for the recovery of the species, consistent with the population and distribution objectives. This criterion considers the assessment of all the information in the table.

d Severity: reflects the population-level effect (high: very large population-level effect, moderate, low, unknown).

e Causal certainty: reflects the degree of evidence that is known for the threat (high: available evidence strongly links the threat to stresses on population viability; medium: there is a correlation between the threat and population viability, e.g., expert opinion; low: the threat is assumed or plausible).

4.2 Description of threats

This section describes the threats outlined in Table 2, emphasizes key points, and provides additional information. The threats are listed individually. Although a number of threats are considered a low level of concern, it is important to take account of their cumulative effects over time. The threats are described below in order of decreasing level of concern.

Subsistence farming, logging and human-caused fires in the wintering area

Forest habitat loss from subsistence farming and logging has been severe on the island of Hispaniola (Haiti and Dominican Republic) where the bulk of the Bicknell’s Thrush population winters (Stattersfield et al. 1998; Rimmer et al. 1999, Rimmer et al., 2005a). Fires caused by people are an additional threat to the Bicknell’s Thrush winter habitat (IBTCG 2010). Only 10% of the original forest cover remains in the Dominican Republic (Stattersfield et al. 1998), while just 2% persists in Haiti (Paryski et al. 1989; Sergile 2008). The rate of deforestation is unlikely to decrease in the near future, given the socio-economic pressures in both countries (Stattersfield et al. 1998; Perdomo and Arias 2008; Sergile 2008). The massive loss of habitat on Hispaniola could be the primary cause of the Bicknell’s Thrush population decline (Aubry and Paradis 2009; IBTCG 2010). A higher proportion of males seem to occupy habitats less disturbed by farming, while females are more likely to be found in more disturbed habitats, which could affect their survival (Townsend et al. 2011). In Cuba, more Bicknell’s Thrush habitat is available since 21% of the island retains forest cover, partly as a result of reforestation since 1960 (Mugica 2008). However, the distribution and size of the Bicknell’s Thrush population wintering in Cuba are not well documented. As a result, the extent to which these forests benefit the Bicknell’s Thrush is unclear. The Sierra Maestra mountain chain in Cuba is the only area where the Bicknell’s Thrush has been located. This area has dense forest cover and benefits from the protection of the Sierra Maestra National Park and the Turquino National Park (Y. Aubry pers. comm. 2015).

The limited availability of wintering habitat makes these threats all the more serious. Furthermore, since only a small proportion of this habitat has protected status, it is very likely that the availability of suitable wintering habitat will continue to decline in the years ahead.

Forestry practices in the breeding range

In Canada, roughly 90% of potential Bicknell’s Thrush breeding habitat is located within managed forest (Aubry and Paradis 2009; COSEWIC 2009) and is therefore subject to forest management. High stem density is an important characteristic of the species’ breeding habitat, such that forest management practices that do not promote the maintenance of high stem density or the creation of suitable habitat--whether harvesting or pre-commercial thinningFootnote 5 – are a threat to this species (Aubry et al., in press). The larger the area affected, the greater the loss of suitable habitat. The area of habitat required to support the species at the current level is unknown.

Stand stem density is related to the age of the regenerating forest, with a higher stem density in the initial stages, followed by a reduction in density as the forest reaches maturity. The time it takes for the development of a forest having a suitable structure and stand density for the species can differ from one part of its range to another. It has been estimated at 10 to 15 years in New Brunswick and Nova Scotia (Bredin and Whittam 2009; Campbell et al. 2005) and likely up to 20 years in Quebec, with climate factors and length of growing season varying as a function of region and elevation.

Pre-commercial thinning is a threat to the species and its habitat, because it is carried out during the period at which stem density is favourable to nesting of the species and during the species’ breeding period (Bredin and Whittam, 2009; Campbell et al. 2005). Pre-commercial thinning also prematurely reduces the quality of suitable habitat. This type of management practice is typically carried out between June and September, which largely corresponds to the nesting period, when the risk of harming or disturbing nests and eggs is the highest (Rousseu and Drolet 2015). As a result, this practice is likely to lead to the direct destruction of nests, eggs and chicks (Environment Canada 2014). It can also disturb nesting attempts.

Thinned stands are not suitable habitat for the Bicknell’s Thrush, but there remains some uncertainty regarding the species’ use of recently pre-commercially thinned stands or unthinned areas remaining within thinned stands (Chisholm and Leonard 2008; Aubry et al. 2011). There is some suggestion that the Bicknell’s Thrush may re‑use pre-commercially thinned stands once the canopy recloses (Chisholm and Leonard 2008; Aubry et al. 2011).

Other silvicultural treatments may also have impacts on the Bicknell’s Thrush and its habitat, although no specific studies have been conducted on them. They include commercial thinning and planting,Footnote 6 which also reduce or modulate stand stem density to promote the growth of crop trees (MRN 2013). In most cases, the resulting stand density does not meet the requirements of the Bicknell’s Thrush. Further studies are needed to determine their impacts.

Lastly, the construction of infrastructure (forest roads, sand pits, etc.) can also have an impact on the Bicknell’s Thrush, including habitat fragmentation, creation of barriers likely to restrict movements and destruction of nests.

Construction of wind farms in the breeding range

The mountain tops used by Bicknell’s Thrush as breeding habitat are the site of wind farm construction. Since wind power is currently experiencing rapid growth, a number of wind farm projects are being proposed and developed in Bicknell’s Thrush habitat (e.g., Caribou Mountain, in New Brunswick, and the Massif du Sud, Terres du Séminaire, Rivière du Moulin, Saint-Robert-Belleramin and Murdochville, in Quebec) (COSEWIC 2009). The construction of wind farms is also anticipated elsewhere in the species’ habitat, for example in the Lower St. Lawrence and Gaspé regions of Quebec, as well as in Nova Scotia, where the sites occupied by the species during the breeding season are also some of the windiest in the province. The development of these sites for wind power is therefore of great economic interest and the pressure to develop these sites will intensify over the coming years (M. Elderkin pers. comm.).

Land clearing for turbine foundation installation, as well as for the construction of access roads and electricity transmission corridors associated with the turbines, results in the permanent loss and fragmentation of Bicknell’s Thrush breeding habitat (Zimmerling et al. 2013). In addition, direct mortality results from collisions with these tall structures, both during migration and during the summer season (Rimmer et al. 2001) (see Collisions with human-made structures).

Clearing for recreational development in the breeding range

In some areas, Bicknell’s Thrush habitat is also threatened by clearing for recreational development such as trails and areas for skiing, hiking, biking and all-terrain vehicles (COSEWIC 2009). Backcountry skiing is increasingly popular in the Gaspé region. In backcountry skiing areas, the objective is to provide skiable areas through bush, such that 60% to 80% of the area is cut. The rest of the area is conserved as small wooded patches (M. Morin pers. comm. 2015).

Development for telecommunications in the breeding range

Bicknell’s Thrush breeding habitat located at high elevations is also threatened by telecommunications development. Such development is escalating in Canada with the rapid increase in cell phones, pagers and digital television (Bredin and Whittam 2009). The construction of telecommunication towers has a similar impact to that of wind turbines, although less severe since a given site typically has only one tower, unlike wind farms, where a number of turbines are generally constructed in the same area. In addition, telecommunication towers are usually accompanied by small buildings surrounded by fences and lighting (Bredin and Whittam 2009), which have an impact on the species’ habitat and can also cause disturbance to the birds themselves. Finally, in the same way as wind turbines, telecommunication towers can cause direct mortality of birds (Rimmer et al. 2001) (see Collision with human-made structures).

Overgrazing by moose in the breeding range

Locally, in areas where moose are hyper-abundant, overgrazing by moose can alter the composition and structure of the forest. Areas that should have regenerated into dense fir-birch stands, characteristic of the first stages of succession, are transformed into open clearings typically dominated by herbaceous vegetation (McLaren et al. 2004). Since the breeding habitat of the Bicknell’s Thrush is primarily composed of Balsam Fir stands, this habitat can sometimes be significantly reduced. Such changes have been observed in northern Cape Breton, Nova Scotia, by Smith et al. (2010) and in the Cascapédia Lake area, in Gaspésie National Park (Y. Aubry, pers. comm. 2015). Smith et al. (2010) conclude that there is a relationship between sustained, intensive moose browsing and alterations to the cyclic successional system between Balsam Fir and Spruce Budworm outbreaks. The impact of intensive moose browsing on the forest has not been studied in other parts of the Bicknell’s Thrush breeding range, but it is conceivable that impacts may exist in areas with a high moose population.

Coastal development along flyways

The flyways used by the Bicknell’s Thrush are not yet well known, but scientists believe that the species migrates along the east coast of North America. While the characteristics of the species’ staging areas have not been studied, coastal development (new buildings, wind turbines, communications towers, etc.) is damaging the habitats of other migratory birds (Moore et al. 1995; Moore 2000). The Bicknell’s Thrush could therefore also be affected by this type of development.

Rats and cats introduced into the wintering area

Introduced rats on the island of Hispaniola attack the Bicknell’s Thrush: five of the 53 (9.4%) birds monitored with transmitters have been the victims of rats (Townsend et al. 2009). Other introduced predators, such as cats, also pose a threat to birds (IBTCG 2010). A study conducted in Canada showed that cats killed 100 to 350 million birds a year in the country. Ground nesting and feeding birds appear to be more vulnerable (Blancher 2013).

Acid precipitations

Nitrogen compounds (nitrates and ammonia) emitted into the atmosphere by the industrial and transportation sectors are deposited at high elevations as acid precipitation; this contributes to the leaching of calcium from soils, a phenomenon that is particularly marked in the northeastern part of the continent (Driscoll et al. 2001). The resulting loss of large quantities of soil calcium could reverberate through the food chain as far as the Bicknell’s Thrush, causing a calcium deficiency that could result in weaker shells, as is the case with other passerine birds from northern Europe that nest in acidified areas (Graveland and Drent 1997; Mand et al. 2000). The calcium leaching caused by acid precipitation (rain, mist and fog) may also act directly on vegetation, particularly with respect to the calcium contained in the cell membranes of spruce needles (DeHayes et al. 1990; 1999). This loss of needle calcium would reduce the spruce trees’ tolerance to low temperatures, and studies suggest that the decline in Red Spruce (Picea rubens) observed in most of its range since the 1960s (Eager and Adams 1992) is related to this phenomenon (DeHayes et al. 1990; 1999). This decline could disturb Bicknell’s Thrush breeding habitat by allowing other less suitable tree species to become established.

Mercury bioaccumulation

High-elevation environments are more prone to airborne contaminant deposition (Rimmer et al. 2005b), and the Bicknell’s Thrush could therefore be exposed to significant concentrations of these contaminants. In addition, the mercury released into the atmosphere from waste incineration and coal burning is a concern because of its capacity to bioaccumulate in the food chain. Researchers have also found significant levels of mercury in Bicknell’s Thrush tissues (Rimmer et al. 2005b; Townsend 2011; Townsend et al. 2013). On the whole, the concentrations were higher in the wintering grounds than in the breeding grounds (Rimmer et al. 2005b; Townsend et al. 2013). However, the effects on physiology and behaviour have not been documented in detail. High concentrations could compromise the birds’ immune systems and cause reduced fecundity (Brasso and Cristol 2008; Hawley et al. 2009; Jackson et al. 2011).

Lead poisoning

High levels of lead have been detected in high-elevation soils in the northeastern United States (Kaste et al. 2006). Research is needed to determine whether exposure to elevated levels of lead or other trace elements in the soils could affect the physiology or behaviour of the Bicknell’s Thrush.

Collisions with human-made structures

As mentioned earlier (see Construction of wind farms and Development for telecommunications in the breeding range), collisions with structures such as communication towers, buildings and other vertical structures have occasionally been reported (Rimmer et al. 2001; Calvert et al. 2013).

Control over natural disturbances

Control over plant succession may alter the availability or quality of Bicknell’s Thrush breeding habitat. The species usually nests in very dense regenerating stands that follow disturbances such as fires or insect infestations. Control over natural disturbances (e.g., fires, insect pests) may result in fewer stands regenerating to a stage where they can be used by the Bicknell’s Thrush for breeding (IBTCG 2010).

Red Squirrel predation

Video monitoring of nests has shown that the Red Squirrel is a major predator of Bicknell Thrush eggs and nests (Y. Aubry unpubl.; VCE unpublished data). Research conducted in the United States has found that Bicknell’s Thrush breeding success is lower in the years following summers with especially abundant Balsam Fir and spruce cone crops, which occurs every other year (Rimmer et al. 2001; Bredin and Whittam 2009). This biennial pattern of breeding success has been traced to population cycles of Red Squirrels, which feed heavily on cones, especially fir and spruce cones (Rimmer et al. 2001; Bredin and Whittam 2009). This situation results in better winter survival of the squirrels, which produce more young the following spring, leading to increased squirrel predation of Bicknell’s Thrush eggs and nestlings. In the Atlantic provinces however, the High Elevation Landbird Program (HELP), which counts the number of squirrels observed on each route annually, has so far not detected any relationship between Red Squirrel numbers and Bicknell’s Thrush abundance in Nova Scotia and New Brunswick (Bredin and Whittam 2009).

Recreational activities

Summer recreational activities at high elevations, such as hiking, mountain biking and ATV use, could pose another threat. While various indicators suggest that the species is able to tolerate a moderate level of human disturbance (Rimmer et al.2001), there are no studies that confirm that the species is tolerant of the above-mentioned activities. It can, however, be said that such activities pose a localized threat, the potential impact of which is more anticipated than real.

Climate change

Climate change could push the forest stands used by breeding Bicknell’s Thrushes to even higher elevations (Iverson et al. 2008; Rodenhouse et al. 2008). Such a change has already been documented in the Green Mountains of New England, where Beckage et al. (2008) estimated that a 91–119 m upslope shift in the lower elevational limit of the spruce-fir zone occurred between 1964 and 2004. This change coincided with a 1° C increase in average temperatures over the same period. Given that the Bicknell’s Thrush already frequently nests at high elevations, displacement to even higher elevations would mean that it would be confined to progressively smaller and more isolated mountain patches. A study conducted on this potential threat indicates that a 1 °C increase in temperature would reduce potential habitat of the Bicknell’s Thrush by more than half, while an increase of 2 °C could eliminate all breeding sites in the Catskill Mountains and most of Vermont (Rodenhouse et al. 2008). A 3 °C increase in growing season temperature could eliminate nearly all the Bicknell’s Thrush habitats in the northeastern United States (IBTCG 2010). However, there is a strong possibility that the species’ range is shifting northward (Cumming et al. 2014). In Canada, a northward shift in the Balsam Fir distribution range could result in the reduction or elimination of the Bicknell’s Thrush population in New Brunswick and Nova Scotia, since the current range of this species is close to the northern boundaries of those provinces.

Climate change could also lead to an increased frequency of tropical storms and other adverse weather conditions (e.g., heavy rain, extreme temperatures). This increase in adverse weather conditions could result in higher nest failure and direct mortality rates for these birds throughout their annual cycle (Angeles et al. 2007; Rodenhouse et al. 2008). More intense and frequent rain and wind storms could reduce foraging opportunities, abnormally cold weather or prolonged heat waves could interfere with thermoregulation, and stronger and more frequent hurricanes could disrupt migrations and damage wintering habitats. It is currently impossible to assess the severity of the potential indirect effects of climate change on the Bicknell’s Thrush.

Climate change also has the potential to affect a variety of environmental and ecological parameters that determine the viability of Bicknell’s Thrush populations (e.g., spread of pests and pathogens that attack forests in the species’ breeding habitat (IBTCG 2010), timing of predator cycles (McCarty 2001), dates of spring prey emergence (Sillett et al. 2000; Sanz et al. 2003; Both et al. 2006) and interspecific competition (Wormworth and Mallon 2006). These effects are not well understood, and research is required to assess their impacts.

5 Population and distribution objectives

The population and distribution objectives for the Bicknell’s Thrush are as follows:

  • in the short term (2016-2026), slow the decline in its population while ensuring that no more than 10% of the population is lost during that period, and ensure that no net loss occurs in its biological area of occupancyFootnote 7 throughout its range in Canada;
  • in the long term (after 2026), ensure a positive population trend over 10 years, as well as a positive trend in the species’ biological area of occupancy, throughout the species’ range in Canada.

The population objectives address the long-term decline of the Bicknell’s Thrush population, the factor that led to its designation as a threatened species in Canada (COSEWIC 2009). In order to take into consideration the fact that the population objectives are based on the species’ demographic trends, the recovery strategy includes approaches for improving population monitoring. The objectives aim to ensure a positive trend over 10 years, without attempting to restore the maximum known population level, given that the significant reduction in the species’ wintering habitat is largely irreversible.

The distribution objectives are based on the biological area of occupancy of the Bicknell’s Thrush, since this datum best reflects the species’ distribution. Owing to its specific habitat requirements, the Bicknell’s Thrush occupies only a small portion of its extent of occurrence.Footnote 8 The distribution objectives cover the species’ entire range in Canada in order to prevent the loss of part of this fragmented range.

A 10-year period is appropriate to assess changes in the species’ population and distribution. This length of time was chosen because halting the decline is a challenge that cannot be met within the span of a few years. In addition, COSEWIC assesses species every 10 years and its assessment criteria include a review of demographic changes over a 10-year period.

These objectives will be reviewed when preparing the report required every five years to assess the implementation of this recovery strategy and measure the progress toward meeting the strategy’s population and distribution objectives (section 46, SARA). The objectives could also be reviewed outside this period in light of new information if this is appropriate for the species’ recovery.

It is important to note that there are some uncertainties regarding attainment of the population and distribution objectives because of the challenge posed by reducing the threats to the species and its wintering habitat. These uncertainties have been identified in the assessment of the feasibility of recovery (see that section, p. iv).

6 Broad strategies and general approaches to meet objectives

6.1 Actions already completed or currently underway

Conservation and stewardship

  • The International Bicknell’s Thrush Conservation Group (IBTCG) was formed in 2007 and includes scientists, natural resource managers and conservation authorities from at least seven countries (IBTCG 2010).
  • The International Bicknell’s Thrush Conservation Group (IBTCG) has published the Conservation Action Plan for Bicknell’s Thrush (IBTCG 2010).
  • Studies have been conducted to quantify the extent of the forests that are used or could be used by the Bicknell’s Thrush in the Canadian part of its breeding range, and to identify landowners so that awareness activities and other types of conservation activities may be undertaken (IBTCG 2010; Broeckaert 2011; Bussière 2012; Y. Aubry pers. comm. 2015).
  • The Bicknell’s Thrush Habitat Protection Fund was created in the United States in 2005. This fund is administered by the Adirondack Community Trust, and its primary purpose is to financially support conservation projects for the Bicknell’s Thrush wintering habitat in the Dominican Republic and Haiti.
  • Guides to best management and stewardship practices for the Bicknell’s Thrush have been prepared for the forestry industry in Nova Scotia, New Brunswick and Quebec (Campbell et al. 2005; Campbell and Whittam 2006; Bredin and Whittam 2009; Rioux and Poulin 2009; Bussière and Julien, 2012a; Bussière and Julien, 2012b) and for the wind power industry (Julien 2012).
  • The Quebec government has developed measures to protect Bicknell’s Thrush pertaining to forest management activities (Gouvernement du Québec 2014).

Demographic monitoring

  • Bird Studies Canada’s High Elevation Landbird Program (HELP) in Nova Scotia and New Brunswick was undertaken between 2002 and 2011 (Campbell and Stewart 2012). A new, improved survey methodology (Mountain BirdWatch 2.0), based on the new protocol for monitoring Bicknell’s Thrush populations of the International Bicknell’s Thrush Conservation Group, was adopted in Nova Scotia and New Brunswick in 2012. This method will ensure long-term, standardized monitoring of the Bicknell’s Thrush throughout its range.
  • In Quebec, partial monitoring of the Bicknell’s Thrush has been carried out by Environment and Climate Change Canada’s Canadian Wildlife Service and by the Regroupement QuébecOiseaux since 1989 (Perreault 2013; Y Aubry pers. comm. 2015). More recently, the Quebec Department of Forests, Wildlife and Parks has conducted monitoring of sites on public lands (MDDEFP 2013).

Research

  • Since 1997, various professional and academic projects on the Bicknell’s Thrush have been undertaken in a number of regions in southern Quebec and the Maritimes (including Rompré et al. 1999; Connolly 2000; Nixon et al. 2001; Connolly et al. 2002; Gardiner 2005; Askanas 2008; Chisholm and Leonard 2008; McKinnon 2009; Askanas 2011; Aubry et al. 2011; McKinnon et al. 2014; Aubry et al. in press).
  • A study that uses solar geolocators attached to the backs of Bicknell’s Thrushes is currently underway to gather more information on the species’ migratory routes as well as on the connectivity in time and space between the breeding and wintering areas (McFarland et al. in prep.).
  • A study is under way to estimate the occupancy rates of the Bicknell’s Thrush in managed forests of northern New Brunswick.

6.2 Strategic direction for recovery

The broad strategies and research and management approaches outlined in this section (Table 3), although worded differently, are essentially the same as those of the Conservation Action Plan for Bicknell’s Thrush (IBTCG 2010) prepared by the International Bicknell’s Thrush Conservation Group.

Table 3. Recovery Planning Table
Threat or Limiting FactorfBroad Recovery StrategyPriorityfGeneral Description of Research and Management Approaches
All threats
Knowledge gaps
Monitoring and researchHigh

Develop and implement standardized protocols for research and monitoring of the species’ population and distribution, their trends, the threats, the species’ ecology as well as the various types of habitat required for its life cycle, including:

  • Determine the distribution and size of the population as well as their trends in the breeding range and wintering area;
  • Determine the relative importance of the existing and potential threats to the species and its habitat;
  • Determine whether unthinned habitat remaining after pre‑commercial thinning can support adequate productivity;
  • Determine whether thinned habitat can once again become suitable after the canopy recloses;
  • Determine the area of unthinned habitat necessary to enable the current breeding population to sustain itself and increase;
  • Determine at what point of maturity a suitable stand becomes no longer favourable to nesting;
  • Determine more precisely the characteristics of the various types of habitat used in the breeding range and the wintering area;
  • Determine the upper limit of human activity that can be allowed in the habitat;
  • Determine whether habitat availability is a significant limiting factor in the breeding area.
All threats Knowledge gapsMonitoring and researchMedium
  • Identify the primary migration routes and increase knowledge related to migration chronology.
All threatsConservation and managementHigh
  • Determine the best measures for promoting conservation and development of each of the three types of breeding habitat as well as the post-breeding habitat.
  • Contribute to the conservation, management and, if required, restoration of the habitat used by the species during migration and wintering.
  • Address the main threats to the species’ habitats and determine the best approaches for eliminating, reducing or mitigating the threats to the species.
All threatsEducation, awareness, stewardship and partnershipHigh
  • Promote national and international collaboration to fill the knowledge gaps and address the threats to the species and its habitat throughout its range.
  • Maintain and improve collaboration among stakeholders in order to address the threats to the species and its habitat throughout its range.
All threatsEducation, awareness, stewardship and partnershipMedium
  • Promote public involvement in habitat protection and species conservation initiatives as well as in the surveying and monitoring activities.
All threatsLegislation and policyMedium
  • Promote compliance with environmental acts, regulations and policies, in particular the Migratory Birds Convention Act, 1994g and its regulations.
  • Encourage the implementation of environmental policies and programs that address the threats on breeding grounds and develop appropriate policies and programs where deficiencies exist.

f “Priority” reflects the degree to which the broad strategy contributes directly to the recovery of the species or is an essential precursor to an approach that contributes to the recovery of the species.

g Environment and Climate Change Canada’s website on incidental take of migratory birds.

6.3 Narrative to support the recovery planning table

Bicknell’s Thrush recovery will require commitment and collaboration among international, federal and provincial jurisdictions, Aboriginal people, local communities, landowners, industry and other interested parties.

Monitoring and research

Standardized protocols are required for monitoring and research activities. Properly designed monitoring activities for determining the size and distribution of the population, as well as their trends, are essential in order to measure achievement of the population and distribution objectives. It is also important to fill the knowledge gaps concerning threats to the species and its habitat. The assessment of threats must be improved in order to determine whether the potential threats actually exist, to take priority action to address the threats of greatest concern, and to determine the most effective action to eliminate, reduce or mitigate those threats. Since there are fewer females than males, particular attention must be paid to the females to determine which threats affect them more, in particular in the wintering habitat. Although certain aspects have yet to be confirmed (e.g., the relationship between the probability of occurrence of the species, latitude and elevation of the forest), the characteristics of the species’ breeding habitat are relatively well known; however, the characteristics of the other types of habitat used by the species in its range (post-breeding habitat, migration habitat) are not well known and merit study since they could play an important role in the species’ recovery. Knowledge about the wintering habitat must also be improved. Given the limited availability of this habitat and the serious threats to it, research to improve knowledge of this habitat must be considered a priority. Information on the species’ migratory routes and the specific migration periods needs to be better documented.

Conservation and management

There are many activities that can affect Bicknell’s Thrush breeding habitat. To minimize or mitigate the impacts of such activities, breeding habitat conservation and management practices will be needed. To that end, a landscapeFootnote 9 approach will have to be adopted. The threats affecting breeding habitat vary, depending on the three habitat types used by the species. This means that the conservation and management measures to be implemented will have to be tailored to each habitat type, taking into consideration habitat dynamics, succession time, and habitat size and shape. Particular efforts will have to be focused on determining the minimum area of habitat required to promote the species’ recovery. In addition, development (e.g., wind farms, telecommunication towers, ski hills) on mountain tops where the species occurs will have to be limited to the extent possible. Although the impact of overgrazing by moose on the species is still not well known, it is clear that it will have to be addressed when and where this proves necessary. The other threats (currently threats with a low level of concern or potential threats) will have to be addressed if necessary.

The conservation and management of the breeding habitat will not be sufficient to ensure the recovery of the Bicknell’s Thrush if no measures are taken for its wintering habitat, the availability of which is considered an important limiting factor for the species. The threats to this habitat, in particular subsistence farming, logging and human-caused fires, are of high concern and improving the situation poses a genuine challenge. This requires international collaboration both in order to fill the knowledge gaps and for the planning and implementation of measures to conserve, improve and, if necessary, restore this habitat. Once research has filled the knowledge gaps concerning the post-breeding habitat and the migration habitat, it will be necessary to determine and carry out the required action. All of these measures should have a positive effect on the other species at risk whose habitat requirements overlap those of the Bicknell’s Thrush (see Appendix D). 

All of the threats that directly affect the Bicknell’s Thrush must be considered in order to eliminate, reduce or mitigate their adverse effects on the species. These threats include predation by rats on wintering grounds and the risks of collisions with communication towers and wind turbines. The presence of environmental contaminants, such as mercury, lead and acid precipitation, raises concerns and it will be necessary to identify and implement appropriate measures to limit their adverse effects on the species.

Education, awareness, stewardship and partnership

As mentioned in the introduction to this section, the recovery of the Bicknell’s Thrush requires the collaboration and commitment of all the stakeholders, both governments and industries, as well as communities and landowners.

International collaboration is essential because of the serious threats to the species’ wintering habitat. To improve the situation on the wintering grounds, it is important to minimize new habitat losses to the extent possible, to protect remaining habitat suitable for the species and, if possible, to increase the area of this habitat. The International Bicknell’s Thrush Conservation Group (IBTCG), in which a number of Canadian organizations and experts participate, is a key contributor to this effort. The IBTCG has developed a conservation plan for the species and is already working on its implementation, including certain components of this recovery strategy. The IBTCG is also working on securing the necessary funding to aid in the implementation of recovery measures in the countries of the Greater Antilles.

The key stakeholders with an interest in the Bicknell’s Thrush must be identified and engaged in a dialogue in order to develop and apply the most appropriate solutions to the threats affecting the Bicknell’s Thrush. Stewardship strategies and appropriate tools must be developed and communicated effectively to the stakeholders. In particular, it is essential to raise the awareness of the key stakeholders concerning the species’ requirements and work with them to develop methods for intervention in the species’ habitat that will promote habitat conservation. Best practice guides have already been prepared or are being developed for forestry activities. Such guides could be supplemented if needed and similar initiatives will have to be developed to address the other threats.

Social acceptance of the measures required for conservation of Bicknell’s Thrush habitat will depend on the effectiveness of efforts to raise public awareness about the existence of the species and its habitat requirements. In addition to reaching the general public, it will also be necessary to encourage participation by individuals and organizations dedicated to environmental conservation in data collection through species surveying and monitoring activities. Some public participation initiatives already exist, such as the High Elevation Landbird Program and eBird.

Legislation and policy

The general prohibitions set out in the Migratory Birds Convention Act, 1994 and its regulations also protect the adults, young, nests and eggs of the Bicknell’s Thrush throughout Canada, regardless of land ownership. During the breeding season, potentially destructive or disturbing activities should be avoided in areas where the species is likely to be found (Environment Canada 2014).

Throughout the species’ range, promotion of compliance with legislation and policies should be a priority. Currently, various legal means exist in order to protect the Bicknell’s Thrush and its habitat in Canada (e.g., species at risk legislation). It is necessary to continue implementing the existing environmental policies and programs on the reduction of the pollutants responsible for acid precipitation and the accumulation of mercury, as well as existing policies and programs on development in the natural environment (e.g., wind farms, telecommunication towers), and to develop appropriate policies and programs where deficiencies exist. It is essential that these means be used to their full potential for the protection of the Bicknell’s Thrush.

7 Critical habitat

SARA defines critical habitat as “... habitat that is necessary for the survival or recovery of a listed species.” Paragraph 41(1)(c) of SARA requires that recovery strategies include an identification of the species’ critical habitat, to the extent possible, as well as examples of activities that are likely to result in its destruction. Under subparagraph 41(1)(c)(1) of SARA, the recovery strategy must also include a schedule of studies to identify the critical habitat of the species where available information is inadequate, as in the case of the Bicknell’s Thrush.

7.1 Identification of the species' critical habitat

On the basis of the best information available, the critical habitat of the Bicknell’s Thrush is partially identified in this recovery strategy. Existing knowledge is insufficient to identify all the critical habitat considered necessary for the species’ recovery. For example, information is needed on the habitat used in the post-breeding period and on the area of habitat necessary for the recovery and survival of the Bicknell’s Thrush at the landscape scale. As new information becomes available, the boundaries of the critical habitat could be revised and new critical habitat units could be identified. A schedule of the studies necessary to complete the identification of critical habitat of the species (section 7.2) is also included.

Critical habitat is identified at locations where the criteria of habitat occupancy and the biophysical attributes of suitable habitat, as explained in the following sections, are met.

7.1.1 Habitat Occupancy

The distribution of the Bicknell’s Thrush can be described as contagious, in the sense that individuals tend to occur in relatively large numbers with other Bicknell’s Thrushes, rather than being uniformly distributed across suitable habitat (Y. Aubry pers. comm. 2016). The home ranges of males largely overlap and are distributed around the home range of one or more females (Collins 2007; Aubry et al. 2011). The presence of one bird therefore suggests that several other birds are also present in the surrounding area. As a result, it is important to define habitat occupancy using known records of the species as a reference point.

Bicknell’s Thrush habitat consists of dense forest stands where it is difficult to obtain observations that would confirm breeding. Most existing data are records of birds heard during the breeding season, which corresponds to possible nesting bird behaviour (see Appendix B for definitions). Habitat occupancy will be established using possible, probable and confirmed breeding records (see Appendix B for definitions). Such records are good indicators of habitat occupancy and suitability.

Habitat occupancy will be determined on the basis of all breeding records obtained during at least one breeding season (June 1 to August 15) in suitable habitat. Given that the Bicknell’s Thrush was elevated to the rank of species in 1995 (American Ornithologists’ Union 1995) and that this triggered, during the same period, the start of inventory work on its breeding range in Quebec, New Brunswick and Nova Scotia, all known records of breeding from 1995 to 2014 are used to define habitat occupancy.

7.1.2 Biophysical Attributes of Suitable Habitat

This criterion for identifying critical habitat refers to the biophysical attributes of the various habitats in which the species can engage in activity associated with breeding (e.g., courtship, territory defence, nest building and foraging) in Canada. Given that the probability of occupancy of a site by the Bicknell’s Thrush is associated with the interaction between habitat quality at the local scale and habitat quality at the landscape scale (Frey et al. 2012), it is important to take both scales into consideration in defining the characteristics of suitable habitat. The local scale is defined by the habitat characteristics that are measured at the breeding site. The landscape scale relates to the spatial-temporal dynamics of the biological and physical components affecting vast regions.

The biophysical attributes of suitable habitat required by the Bicknell’s Thrush to carry out its activities at the local scale are generally defined by the presence of conifer stands (comprising 75% of stand basal area) or very dense, relatively unfragmented mixedwood stands dominated by Balsam Fir (comprising 50–75% of stand basal area [MRNF 2011]). The biophysical attributes at the local scale correspond to the following definitions for each of the three types of breeding habitat found at the landscape scale:

  • High-elevation montane forest (elevation of ≥ 750 m in New Brunswick, ≥ 440 m in Nova Scotia and ≥ 600 m in Quebec)
    • Dense coniferous forests (between 10,000 and 50,000 stems/ha), typically not managed for forest harvesting. They can be characterized by Balsam Fir stands affected by regenerating fir waves. On some sites, such as exposed ridgelines or along edges of human-created openings, they can be characterized by the presence of stunted firs due to high winds and heavy winter snow and ice accumulation. These stands are also characterized by the low height of mature trees and by a low growth rate, due to the harsh climate conditions at high elevations. In these environments, Balsam Fir can sometimes be accompanied, to a lesser extent, by White Birch (Betula papyrifera), Red Spruce, White Spruce (Picea glauca), Black Spruce, Mountain Ash and other deciduous species.
  • High-elevation managed forests (minimum elevation ≥ 380 m)
    • Dense conifer stands (10,000 to 50,000 stems/ha), generally managed for forest harvesting, characterized by the presence of standing conifer snags and dense balsam fir regeneration following human or natural disturbance, from the sapling stage, Footnote 10 with a height of over 2 to 3 m, to a stage at which stand structure and density become unsuitable. At some sites in the Maritimes, a high density of small white birch stems and the presence of leaf litter on the ground appear to be important components of the species’ habitat (Nixon et al. 2001; Campbell and Whittam 2006);
      Or
    • Dense (10,000 to 50,000 stems/ha) mixedwood stands (50% to 75% conifers), generally managed for logging purposes, characterized by regeneration dominated by balsam fir following clearcutting, fire or other disturbances.
  • Coastal lowland forest (elevation < 380 m)
    • Dense (10,000 to 50,000 stems/ha) maritime spruce-fir forests, generally harvested to only a small extent or not at all, located where cool sea breezes and high precipitation levels reproduce the characteristics of high-elevation forests.

At the site scale, habitat that is currently suitable for breeding Bicknell’s Thrushes can become unsuitable for breeding as the stand ages or if it is subject to natural or human disturbance. Due to these spatial-temporal habitat dynamics and to the fact that the species tends to have contagious distributions (Y. Aubry pers. comm. 2016), it is critical to maintain availability of suitable habitat not only at the scale of the breeding site, but also at the landscape scale. Using the landscape scale makes it possible to maintain suitable habitat at two scales. It must also include habitats that, although they do not currently have biophysical attributes suitable to the species, have the potential to evolve towards suitable habitat, in order to ensure constant availability of suitable habitat in time and space. As a result, stands within a 5 km radius of a known record of the Bicknell’s Thrush that are dominated by balsam fir, but whose stem density or structure is not suitable because the trees are too young or too old, are also considered critical habitat if they have the potential to regenerate into suitable habitat as part of the natural succession process. Similarly, areas within a 5 km radius of a known record that have been disturbed (e.g. logging, windthrow) and that are likely to regenerate into a type of stand with appropriate species composition and stem density are also considered critical habitat.

To ensure that the recovery objectives are met, a minimum area of critical habitat must be maintained at the landscape scale, and appropriate landscape-scale conservation objectives must be developed. The current lack of knowledge means that the minimal habitat area and appropriate conservation objectives cannot be precisely determined. An activity was included in the schedule of studies (section 7.2) to fill this knowledge gap. This information is also important to ensure a better assessment of what constitutes destruction of critical habitat.

As mentioned above, at the landscape scale, the area of suitable habitat that must be considered critical habitat for high-elevation montane forests, for high-elevation managed forests and for coastal lowland forests remains unknown. A study on the Bicknell’s Thrush in a high-elevation montane forest environment in Vermont estimated that when the proportion of suitable Bicknell’s Thrush habitat within 5 km of a roughly 600-ha patch of suitable habitat reaches a minimum threshold of 0.10 (10%), the probability of occupancy by the species is approximately 1.0 (100%) (Frey et al., 2012). This study indicates that the probability of occupancy of suitable habitat depends on the interaction between habitat conditions at the local (breeding site) scale and those at the landscape scale. Although the study was carried out only in a high-elevation montane forest environment and although it is impossible to rigorously apply the conditions of the study by Frey et al. (2012), it was decided that a radius of 5 km around a breeding record would be adopted as a boundary for identifying critical habitat, for the three types of Bicknell’s Thrush breeding habitat. The use of an area of 5 km around possible, probable and confirmed Bicknell’s Thrush breeding records corresponds favourably to the potential habitat areas identified by the habitat model of the Vermont Center for Ecostudies (Lambert et al. 2005) when applied to Canada (Y. Aubry, pers. comm. 2015), and thus supports the choice of a radius of 5 km as a boundary for critical habitat. It has been determined that a 5 km radius is likely to ensure the long-term presence of suitable habitat for the species, in a context where the distribution of the habitat is dynamic in time and space. An activity designed to determine whether using a 5 km radius for the identification of critical habitat captures a large enough area to include all the suitable habitat was entered in the schedule of studies (section 7.2).

The biophysical attributes of habitat during the post-breeding period are not known. An activity was entered in the schedule of studies (section 7.2) to indicate the need to develop further knowledge in this area before we can identify critical habitat for this period. The same is true for knowledge with respect to the species’ social structure. A better understanding of the influence of the species’ social behaviour on habitat selection and use could improve the identification of critical habitat.

7.1.3 Application of Critical Habitat Identification Criteria

Critical habitat for the Bicknell’s Thrush is partially identified in this recovery strategy. It corresponds to areas of suitable habitat and areas with the potential to become suitable habitat that are contained within a 5 km radius polygon centred on all coordinates representing a possible, probable or confirmed breeding record obtained between June 1 and August 15, from 1995 to 2014. When 5 km radius polygons overlap, they are merged into a single polygon. Each of the polygons represents a critical habitat unit. A schedule of studies (Table 4) outlines the activities required to complete the identification of critical habitat.

The application of the criteria described in sections 7.1.1 and 7.1.2 identifies 58 critical habitat units for Bicknell’s Thrush in Canada: 43 in Quebec, 11 in New Brunswick and 4 in Nova Scotia. The critical habitat units for Bicknell’s Thrush in Canada are presented in Appendix C (tables C-1, C-2 and C-3 and in figures C-1 to C-12). Critical habitat for Bicknell’s Thrush in Canada occurs within the polygons shaded in yellow shown on each map, where the criteria and methodology described in this section for identifying critical habitat are met. More detailed information on critical habitat to support protection of the species and its habitat may be requested on a need-to-know basis by contacting Environment and Climate Change Canada – Canadian Wildlife Service at ec.planificationduretablissement-recoveryplanning.ec@canada.ca.

Existing human structures (e.g., communication towers, wind turbines, roads, houses, ski runs) and other areas that do not have the biophysical characteristics of suitable habitat for Bicknell’s Thrush are not identified as critical habitat.

7.2 Schedule of studies to identify critical habitat

Current knowledge is insufficient to identify all critical habitat of the Bicknell’s Thrush. Table 4 describes the activities that must be carried out to complete the critical habitat identification or to specify the boundaries. It is important to verify whether the decision to identify critical habitat on the basis of a 5 km radius is adequate for achieving the population and distribution objectives. It is also important to establish the minimum area of suitable habitat to be maintained at the landscape scale for the three types of breeding habitat, to ensure that the critical habitat can fully play its role in the recovery of the Bicknell’s Thrush. The critical habitat identification will be updated in a revised version of the recovery strategy or in an action plan, once sufficient new knowledge has been acquired to determine the critical habitat required to meet the objectives.

Table 4. Schedule of studies to identify critical habitat
Description of ActivityRationaleTimeline
Verify whether a 5 km radius around a record is adequate for achieving the population and distribution objectives.This activity is required in order to better support the decision to identify critical habitat on the basis of a 5 km radius. It will make it possible to determine whether the radius should be increased.2016-2021
Establish the minimum area of suitable habitat to be maintained for the three types of breeding habitat.This activity is required in order to determine, for each of the three types of breeding habitat, the minimum area of suitable habitat to be maintained to achieve the population and distribution objectives.2016-2021
Establish landscape-scale habitat conservation criteria.This activity is required in order to establish the best conservation criteria or action levels to be implemented and to subsequently verify their effectiveness, which could have an impact on critical habitat identification.2016-2021
Increase knowledge of the social structure of the species.This activity is required to specify how the behaviour of the Bicknell’s Thrush influences habitat selection, use and productivity. This knowledge will contribute to specifying the area of critical habitat required to achieve the population and distribution objectives.2016-2021
Characterize suitable habitat used by the species during the post-breeding period and verify its use.This activity is required to identify additional critical habitat units, as there is currently very little information for identifying and characterizing the habitat used by this species during the post-breeding period.2016-2021

7.3 Activities likely to result in the destruction of critical habitat

An understanding of what constitutes destruction of critical habitat is required for the protection and management of critical habitat. Destruction is determined on a case by case basis. Destruction occurs when part of the critical habitat is degraded, either permanently or temporarily, such that it can no longer serve its function when needed by the species. Destruction may result from a single activity or multiple activities at one point in time or from the cumulative effects of one or more activities over time.

The breeding habitat of Bicknell’s Thrush consists of dense forest (over 10,000 stems/ha). Activities likely to reduce stem density may destroy or degrade critical habitat. Activities that lead to the elimination of dense fir stands also have the same effect.

The critical habitat of the Bicknell’s Thrush in high-elevation managed forests is, by definition, subject to forest management activities, which can have effects similar to those of natural disturbance regimes by generating conditions favourable to the creation of suitable habitat. It is important that forest management practices take the needs of the Bicknell’s Thrush into account and that sufficient suitable habitat be maintained within critical habitat units to support the achievement of the population and distribution objectives.

Given the dynamic nature of the critical habitat of the Bicknell’s Thrush in Canada, areas of critical habitat that lose their suitability due to forest aging or human activity can be replaced by other habitat areas that are currently unsuitable but that have the potential to become suitable. This can occur either through natural vegetation succession or through the implementation of management measures that directly favour the presence of dense fir stands (between 10,000 and 50,000 stems/ha). It is therefore important that the planning of human activity within the 5 km radius area containing critical habitat be carried out with the objective of maintaining, at all times, a critical habitat area that can contribute to achieving the population and distribution objectives.

Efforts should also be made to maintain dense fir stands in the high-elevation managed forests currently occupied by the Bicknell’s Thrush for as long as possible to ensure high-quality breeding habitat. Where human activity, such as forest management, is present, it is important that planned forest treatments maintain the availability of dense fir stands (over 10,000 stems/ha when the stand reaches the sapling stage) within the boundaries of the critical habitat over time. To this end, appropriate forest treatments must be implemented at suitable sites to promote regeneration of dense fir stands.

The following list provides examples of activities that are likely to result in the destruction of critical habitat. The activities described in Table 5 are not an exhaustive list. They were selected on the basis of the threats assessed and described in section 4 (Threats) of this recovery strategy. For some of the activities, the determination of thresholds could make it possible to more accurately describe the various aspects likely to result in the destruction of critical habitat by a specific activity.

Table 5. Examples of activities likely to result in the destruction of critical habitat
Description of ActivityDescription of EffectDetails of Effect
Pre-commercial thinning

Direct impact on critical habitat, whether it is considered suitable habitat or potential suitable habitat.

Given that the Bicknell’s Thrush occurs in forests with a high stem density (between 10,000 and 50,000 stems/ha), a forest whose stem density has been reduced to less than 10,000 stems/ha no longer has the biophysical characteristics of critical habitat for the species.

Destruction of critical habitat.

Once the landscape-scale habitat requirements are determined, pre‑commercial thinning outside the breeding season may not result in the destruction of critical habitat if long-term planning of forest operations ensures the availability of sufficient suitable habitat over time and within the critical habitat boundaries.

Pre-commercial thinning carried out in habitat known to have been recently occupied by Bicknell’s Thrushes would be considered an activity likely to destroy critical habitat.

Clearcutting and selection cutting

Direct impact on critical habitat by reducing the amount of suitable habitat available.

Certain types of treatments can reduce stem density and create canopy openings, which reduces the area or modifies the suitable breeding habitat for the Bicknell’s Thrush. The larger the area treated, the higher the habitat loss and the greater the risk of homogenization of the landscape.

In mixedwood stands (dominated by fir), forest harvesting can favour the regeneration of deciduous species to the detriment of fir.

Following certain treatments (partial cuts, cleaning and release) in dense fir forests, stand composition can be modified due to the increased presence of spruce or deciduous species, which alters the biophysical characteristics of the critical habitat.

These types of treatment (e.g., clearcutting) are normally not carried out in suitable habitat. However, the planning of these treatments will influence the availability of suitable habitat at the landscape scale in time and space.

These types of treatment can have a direct impact on the availability of potential suitable habitat if they result in treated areas that no longer have suitable tree species or density.  

Degradation or destruction of critical habitat.

Once the landscape-scale habitat requirements are determined, clearcutting or selection cutting may not result in the destruction of critical habitat if long-term planning of forest operations ensures the availability of sufficient suitable habitat over time and within the critical habitat boundaries.

Control of insect pests (e.g., Spruce Budworm)

Direct impact on critical habitat, whether it is considered suitable habitat or potential suitable habitat.

Forest activities designed to reduce regeneration of fir in order to reduce the intensity and size of habitat areas affected by insect pests may lead to a reduction in the area of critical habitat for the Bicknell’s Thrush.

Degradation or destruction of critical habitat.

Once the landscape-scale habitat requirements are determined, the control of insect pests may not result in the destruction of critical habitat if long-term planning of forest operations ensures the availability of sufficient critical habitat over time and within the boundaries of the critical habitat.

Plantations

Direct impact on critical habitat considered potential suitable habitat.

Plantations result in a species or stem density that does not create the biophysical attributes required for critical habitat.

A direct impact of plantations is that they affect the availability of critical habitat at the landscape scale in time and space.

Destruction of critical habitat.

Once the landscape-scale habitat requirements are determined, plantations and the application of herbicides (see also the following activity) may not result in the destruction of critical habitat if long-term planning of forest operations ensures the availability of sufficient suitable habitat over time and within the boundaries of the critical habitat.

Tending and sanitation operations

Direct impact on critical habitat considered potential suitable habitat and on the availability of critical habitat considered suitable habitat.

Tending and sanitation operations (mechanical stand release and application of herbicides) are often done in plantations or regenerating natural stands. When these activities are carried out in regenerating natural stands, they reduce stand density and the availability of suitable habitat.

Tending and sanitation operations in plantations do not have an impact on critical habitat since plantations are not considered suitable habitat or potential suitable habitat.

The application of herbicides and other vegetation control measures also have an impact on stand density, on the species present in the stands immediately following treatments and on stand development. The amount of suitable habitat and potential suitable habitat can therefore be affected.

Degradation or destruction of critical habitat.

Once the landscape-scale habitat requirements are determined, tending and sanitation operations carried out outside the breeding season may not result in the destruction of critical habitat if long-term planning of forest operations ensures the availability of sufficient suitable habitat over time and within the critical habitat boundaries.

A vegetation management activity carried out in habitat known to have been recently occupied by Bicknell’s Thrushes would be considered an activity likely to destroy critical habitat.

Forest road / access road construction

Direct impact on critical habitat by reducing the amount of suitable habitat available.

Such infrastructure creates openings in the habitat and causes habitat fragmentation. There is also a net loss of suitable habitat area. Habitat alterations become permanent and irreversible.

Destruction of critical habitat.

Once the landscape-scale habitat requirements are determined, the construction of forest roads or access roads outside the breeding season may not result in the destruction of critical habitat if long-term land use planning ensures the availability of sufficient suitable habitat over time and within the critical habitat boundaries.

Existing forest roads and access roads are not included in critical habitat identification; as a result, road maintenance work is not considered an activity that is likely to result in the destruction of critical habitat.

Transmission line construction

Direct impact on critical habitat by reducing the amount of suitable habitat available.

Such infrastructure creates openings in the habitat and causes habitat fragmentation. There is also a net loss of suitable habitat area. Habitat alterations become permanent and irreversible.

Destruction of critical habitat.

Once the landscape-scale habitat requirements are determined, the construction of transmission lines outside the breeding season may not result in the destruction of critical habitat if long-term land-use planning ensures the availability of sufficient suitable habitat over time and within the critical habitat boundaries.

Maintenance of existing transmission lines is not considered an activity that is likely to result in the destruction of critical habitat.

Clearing for wind turbine and communications tower corridors

Direct impact on critical habitat by reducing the amount of suitable habitat available.

Such infrastructure creates openings in the habitat and causes habitat fragmentation. There is also a net loss of suitable habitat area. Habitat alterations become permanent and irreversible.

Destruction of critical habitat.

Once the landscape-scale habitat requirements are determined, clearing for wind turbine and communications tower corridors outside the breeding period may not result in the destruction of critical habitat if long-term planning of land-use development ensures the availability of sufficient suitable habitat over time and within the critical habitat boundaries.

Maintenance of already wooded areas around wind farms and communications towers is not considered an activity that is likely to result in the destruction of critical habitat.

Trail development, ski area development

Direct impact on critical habitat by reducing the amount of suitable habitat available.

The creation of trails or ski runs requires the felling of stands in areas targeted for this type of development.

Habitat alterations become permanent and irreversible.

Destruction of critical habitat.

Once the landscape-scale habitat requirements are determined, the development of trails or ski areas outside the breeding season may not result in the destruction of critical habitat if long-term land use planning ensures the availability of sufficient suitable habitat over time and within the critical habitat boundaries.

Maintenance of already wooded areas around trails and ski resorts is not considered an activity that is likely to result in the destruction of critical habitat.

8 Measuring progress

The performance indicators presented below provide a way to define and measure progress toward achieving the population and distribution objectives.

The performance indicators for the recovery of the Bicknell’s Thrush are as follows:

In the short term

  1. The decline in the Bicknell’s Thrush population has been slowed such that the Canadian population of this species has not decreased by more than 10% from 2016 to 2026.
  2. No net loss has occurred in its biological area of occupancy throughout its Canadian range from 2016 to 2026.

In the long term

  1. After 2026, a positive 10-year demographic trend, measured by BBS and other available data (e.g., targeted surveys) is achieved (i.e., the population is increasing).
  2. After 2016, the size of the species’ biological area of occupancy increases throughout its Canadian range.

9 Statement on action plans

One or more action plans detailing the measures to be taken to implement this recovery strategy will be posted on the Species at Risk Public Registry within five years after the posting of the final recovery strategy.

10 References

American Ornithologists’ Union. 1995. Fortieth supplement to the American Ornithologists’ Union check-list of North-American Birds. Auk 112:819-830.

Angeles, M.E., J.E. Gonzalez, D.J. Erickson III and J. L. Hernández. 2007. Predictions of future climate change in the Caribbean region using global general circulation models. International Journal of Climatology 27:555-569.

Askanas, H.W. 2008. Does mating system affect the physiological stress of provisioning birds? A comparative study of polygynandrous Bicknell’s thrush (Catharus bicknelli) and socially monogamous Swainson’s thrush (Catharus ustulatus) breeding sympatrically. Master’s thesis, University of New Brunswick, Fredericton, New Brunswick, Canada.

Askanas, H.W. 2011. The Physiological Stress of Two Closely-related Songbirds during Their Breeding Season: the Polygynandrous Bicknell’s Thrush (Catharus bicknelli) and the Socially Monogamous Swainson’s Thrush (Catharus ustulatus). Picoides 24(1):15.

Aubry, Y. and S. Paradis. 2009. Conservation de la Grive de Bicknell au Québec: la contribution des aires protégées. Le Naturaliste Canadien 133(3):22-25.

Aubry, Y., A. Desrochers and G. Seutin. 2011. Response of Bicknell’s Thrush (Catharus bicknelli) to boreal silviculture and forest stand edges: a radio-tracking study. Can. J. Zool. 89:474-482.

Aubry, Y., A. Desrochers and G. Seutin. In press. Regional patterns of habitat use by a threatened forest bird, the Bicknell’s Thrush, in Quebec.

Beckage, B., B. Osborne, D.G. Gavin, C. Pucko, T. Siccama and T. Perkins. 2008. A rapid upward shift of a forest ecotone during 40 years of warming in the Green Mountains of Vermont. Proc. Natl. Acad. Sci. 105(11):4197-4202.

Blancher, P. 2013. Estimated number of birds killed by house cats (Felis catus) in Canada. Avian Conservation and Ecology 8(2):3.

Both C., S. Bouwhuis, C.M. Lessells and M.W. Visser. 2006. Climate change and population declines in a long-distance migratory bird. Nature 441: 81-83.

Brasso, R. and D. Cristol. 2008. Effects of mercury exposure on the reproductive success of tree swallows (Tachycineta bicolor). Ecotoxicology 17:133-141.

Bredin, K. and B. Whittam. 2009. Conserving the Bicknell's Thrush: Stewardship and Management Practices for Nova Scotia's High Elevation Forest. Bird Studies Canada – Atlantic Region, 23 p.

Broeckaert, M. 2011. Réalisation cartographique de la potentialité de l’habitat de la Grive de Bicknell par le biais d’une analyse factorielle de la niche écologique, au Québec, en 2011. Regroupement QuébecOiseaux, 38 p.

Bussière, F. 2012. État des connaissances sur la Grive de Bicknell et des impacts de l’aménagement forestier. Regroupement QuébecOiseaux, Montreal, 31 p.

Bussière, F. and M.-F. Julien. 2012a. Planifier l’aménagement du territoire pour la protection de l’habitat de la Grive de Bicknell sur les terres publiques provinciales. Portrait de la situation et recommandations pour les régions de la Gaspésie et du Bas-Saint-Laurent. Regroupement QuébecOiseaux, Montreal, 50 p.

Bussière, F. and M.-F. Julien. 2012b. Planifier l’aménagement du territoire pour la protection de l’habitat de la Grive de Bicknell sur les terres publiques provinciales. Portrait de la situation et recommandations pour la région de la Capitale-Nationale. Regroupement QuébecOiseaux, Montreal, 49 p.

Calvert, A.M., C.A. Bishop, R.D. Elliot, E.A. Krebs, T.M. Kydd, C.S. Machtans and G.J. Robertson. 2013. A synthesis of human-related avian mortality in Canada. Avian Conservation and Ecology 8(2):11.

Campbell, G., B. Whittam and S. Chisholm. 2005. Bicknell’s Thrush in New Brunswick Forests: What we know, what we need to know and how the forest industry can help. Bird Studies Canada – Atlantic Region, 6 p.

Campbell, G. and B. Whittam. 2006. Bicknell’s Thrush Habitat in Nova Scotia’s Industrial Forest. Bird Studies Canada – Atlantic Region, 17 p.

Campbell, G.B. and B. Stewart. 2012. High elevation landbird program – 10 year report. Bird Studies Canada – Atlantic Region, 19 p.

Centre de données sur le patrimoine naturel du Québec. 2015. Extractions du système de données pour le territoire du Québec. Ministère des Forêts, de la Faune et des Parcs, Québec.

Chisholm, S.E. and M.L. Leonard. 2008. Effect of forest management on a rare habitat specialist, the Bicknell’s Thrush (Catharus bicknelli). Canadian Journal of Zoology 86:217-223.

Collins, B.B. 2007. Spatial Analysis of Home Range, Movement Patterns, and Behavioral Ecology of Bicknell’s Thrush, Catharus bicknelli, in Vermont, Master’s thesis, Antioch University, Keene, New Hampshire.

Connolly, V. 2000. Characterization and classification of Bicknell’s Thrush (Catharus bicknelli) habitat in the Estrie region, Québec. Master’s thesis. McGill University. Montreal, Quebec, Canada.

Connolly, V., G. Seutin, J.-P. L. Savard and G. Rompré. 2002. Habitat use by Bicknell’s Thrush in the Estrie region, Quebec. Wilson Bulletin 114(3):333-341.

COSEWIC. 2009. COSEWIC Assessment and Status Report on the Bicknell’s Thrush (Catharus bicknelli) in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. vii + 44 p.

COSEWIC. 2013. Instructions for the Preparation of COSEWIC Status Reports. Committee on the Status of Endangered Wildlife in Canada. Ottawa. 36 p.

Cumming, S.G., D. Stralberg, K.L. Lefevre, P. Sólymos, E.M. Bayne, S. Fang, T. Fontaine, D. Mazerolle, F.K.A. Schmiegelow and S.J. Song. 2014. Climate and vegetation hierarchically structured patterns of songbird distribution in the Canadian boreal region. Ecography 37(2):137-151.

DeHayes, D.H., C.E. Waite, M.A. Ingle and M.W. Williams. 1990. Winter injury susceptibility and cold tolerance of current and year-old needles of red spruce trees from several provenances. Forest Science 36(4):982-994.

DeHayes, D.H., P.G. Schaberg, G.J. Hawley and G.R. Strimbeck. 1999. Acid rain impacts on calcium nutrition and forest health. Bioscience 49(10):789-800.

Driscoll, C.T., G.B. Lawrence, A.J. Bulger, T.J. Butler, C.S. Cronan, C. Eagar, K.F. Lambert, G.E. Likens, J.L. Stoddard and K.C. Weathers. 2001. Acidic deposition in the northeastern United States: sources and inputs, ecosystem effects, and management strategies. BioScience 51:180-198.

Eager, C. and M.B. Adams. 1992. Ecology and decline of red spruce in the eastern United States, Springer-Verlag, New York., 417 p.

Environment Canada. 2014. Avoidance Guidelines on Incidental Take. Environment Canada, Gatineau, QC.

Evans, W.R. 1994. Nocturnal flight calls of Bicknell’s Thrush, Wilson Bulletin 106:55-61.

Frey, S.J.K., C.C. Rimmer, K.P. McFarland and S. Menu. 2008. Identification and sex determination of Bicknell’s Thrushes using morphometric data. Journal of Field Ornithology 79(4):408-420.

Frey, S.J.K., A.M. Strong and K.P. McFarland. 2012. The relative contribution of local habitat and landscape context to metapopulation processes: a dynamic occupancy modeling approach. Ecography 35(7): 581-589. DOI: 10.1111/j.1600-0587.2011.06936.x.

Gardiner, R. 2005. The long-term effects of pre-commercial thinning on Bicknell’s Thrushes and four other high elevation songbirds in the New Brunswick highlands. B.Sc. Honours Thesis, Mount Allison University, Sackville, NB.

Gouvernement du Québec. 2014. Mesure de protection de la grive de Bicknell à l’égard des activités d’aménagement forestier, Québec. Sous-comité faune de l’Entente administrative, 26 p.

Graveland, J. and R.H. Drent. 1997. Calcium availability limits breeding success of passerines on poor soils. Journal of Animal Ecology 66:279-288.

Hart, J.A., Y. Aubry, K.P. McFarland, B. Whittam, J.D. Lambert and J. Saltman. In prep. A unified distribution model for breeding Bicknell’s Thrushes in U.S. and Canada.

Hawley, D., K. Hallinger and D. Cristol. 2009. Compromised immune competence in free-living tree swallows exposed to mercury. Ecotoxicology 18:499-503.

IBTCG. 2010. A Conservation Action Plan for Bicknell’s Thrush (Catharus bicknelli). J.A. Hart, C.C. Rimmer, R. Dettmers, R.M. Whittam, E.A. McKinnon and K.P. McFarland. International Bicknell’s Thrush Conservation Group.

Iverson, L., A. Prasad and S. Matthews. 2008. Modeling potential climate change impacts on trees of the northeastern United States, Mitigation and Adaptation Strategies for Global Change 13:487-516.

Jackson, A.K., D.C. Evers, M.A. Etterson, A.M. Condon, S.B. Folsom, J. Detweiler, J. Schmerfeld and D.A. Cristol. 2011. Mercury Exposure Affects the Reproductive Success of a Free-Living Terrestrial Songbird, the Carolina Wren (Thryothorus ludovicianus). The Auk 128(4):759-769.

Julien, M.-F. 2012. Comprendre et atténuer les impacts du développement éolien au Québec sur la Grive de Bicknell. Regroupement QuébecOiseaux, Montreal, 39 p.

Kaste, J.M., B.C. Bostick and A.W. Schroth. 2006. Fate and speciation of gasoline‑derived lead in organic horizons of the Northeastern USA. Soil Science Society of America Journal 70: 1688-1698. Mand, R., V. Tilgar and A. Leivits. 2000. Calcium, snails, and birds: a case study. Web Ecology 1:63-69.

Lambert, J.D., K.P. McFarland, C.C. Rimmer, S.D. Faccio and J.L. Atwood. 2005. A practical model of Bicknell’s Thrush distribution in the northeastern United States. Wilson Bulletin 117:1-11.

Mand, R., V. Tilgar and A. Leivtis. 2000. Calcium, snails, and birds: a case study. Web Ecology 1:63-69.

McCarty, J.P. 2001. Ecological consequences of recent climate change. Conservation Biology 15:320-331.

McFarland, K.P., C.C. Rimmer, J.E. Goetz, Y. Aubry, J.M. Wunderle, Jr., A. Sutton, J.M. Townsend, A. Llanes Sosa and A. Kirkconnell. 2013. A winter distribution model for Bicknell’s thrush (Catharus bicknelli), a conservation tool for a threatened migratory songbird. PLOS One 8: e53986.

McFarland, K.P, Y. Aubry, C.C. Rimmer, B. Whittam, J. Townsend, B. Stewart, G. Campbell, R. Renfrew, P. Marra, S. Paradis, V. Afanaseyev and J.W. Fox. In prep. Using light-level geolocation to illuminate migratory routes, stop-over sites and population connectivity for Bicknell’s Thrush (Catharus bicknelli).

McKinnon, E.A. 2009. Bicknell's Thrush (Catharus bicknelli) in managed forests: nest‑site selection, diet, and co-occurrence with Swainson's Thrush (C. ustulatus). M.Sc. Thesis, University of New Brunswick, Fredericton, New Brunswick. 127 p.

McKinnon, E.A., H. Askanas and A.W. Diamond. 2014. Nest-patch characteristics of Bicknell’s Thrush in regenerating clearcuts, and implications for precommercial thinning. Northeastern Naturalist 21(2):259-270.

McLaren, B.E., B.A. Roberts, N. Djan-Chékar and K.P. Lewis. 2004. Effects of overabundant moose on the Newfoundland landscape. Alces 40:45-59.

MDDEFP. 2013. Protocole d’inventaire de la Grive de Bicknell et de son habitat – Novembre 2013. Ministère du Développement durable, de l’Environnement, de la Faune et des Parcs, secteur de la faune. 20 p.

Moore, F.R., S.A. Gauthreaux, Jr., P. Kerlinger and T.R. Simons. 1995. Habitat requirements during migration: important link in conservation. Pages 121-144 in T.E. Martin and D.M. Finch, eds. Ecology and Management of Neotropical Migratory Birds: A Synthesis and Review of Critical Issues. Oxford University Press, New York, NY.

Moore, F. R. [Ed]. 2000. Stopover ecology of Nearctic-Neotropical landbird migrants: habitat relations and conservation implications. Studies in Avian Biology 20.

MRNF. 2011. Norme de stratification écoforestière- Quatrième inventaire écoforestier, Forêt Québec, Direction des inventaires forestiers, Ministère des Ressources naturelles et de la faune. 92 p.

MRN. 2013. Le guide sylvicole du Québec, Tome 2. Les concepts et l’application de la sylviculture, collective work under the supervision of C. Larouche, F. Guillemette, P. Raymond and J.-P. Saucier, Les Publications du Québec, 744 p.

Mugica, S. A. 2008. Cuba. Pages 119-142, in Important Bird Areas in the Caribbean: Key Sites for Conservation (D.A. Wege and V. Anadon-Irizarry, Eds.). BirdLife International, Cambridge, UK.

NatureServe. 2013. NatureServe Explorer: An online encyclopedia of life [Web application]. Version 7.1. NatureServe, Arlington, Virginia. [Accessed July 12, 2013].

Nixon, E.A., S.B. Holmes and A.W. Diamond. 2001. Bicknell’s Thrushes (Catharus bicknelli) in New Brunswick clear cuts: their habitat associations and co-occurrence with Swainson’s Thrushes (Catharus ustulatus). Wilson Bulletin 113:33-40.

Paryski, P., C. A. Woods and F. Sergile. 1989. Conservation strategies and the preservation of biological diversity in Haiti, pp. 855-878. In C.A. Woods (ed.), Biogeography of the West Indies: Past, Present, Future. Sandhill Crane Press, Gainesville, FL.

Perdomo, L. and Y. Arias. 2008. Dominican Republic. Pages 157-174 in Important Bird Areas in the Caribbean: Key Sites for Conservation (D.A. Wege and V. Anadon-Irizarry, Eds.). BirdLife International, Cambridge, UK.

Perreault, G. 2013. Suivi des oiseaux nichant en altitude (SONA) – Rapport d’activité 2012. Regroupement QuébecOiseaux, Montreal, 22 p.

Rimmer, C.C., K.P. McFarland and J.E. Goetz. 1999. Distribution, habitat use, and conservation status of Bicknell's Thrush in the Dominican Republic, El Pitirre 12:114.

Rimmer, C.C. and K.P. McFarland. 2000. Migrant stopover and postfledging dispersal at a montane forest site in Vermont. Wilson Bulletin 112:124-136.

Rimmer, C.C., K.P. McFarland, W.G. Ellison and J.E. Goetz. 2001. Bicknell's Thrush (Catharus bicknelli), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America.

Rimmer, C.C., E. Garrido G. and J.L. Brocca. 2005a. Ornithological field investigations in La Visite National Park, Haiti, 26 January – 1 February 2005, Unpublished report, Vermont Institute of Natural Science, Woodstock, Vermont.

Rimmer, C.C., K P. McFarland, D.C. Evers, E.K. Miller, Y. Aubry, D. Busby and R.J. Taylor. 2005b. Mercury concentrations in Bicknell’s Thrush and other insectivorous passerines in montane forests of northeastern North America. Ecotoxicology 14:223-240.

Rioux, J. and J.-F. Poulin. 2009. Portrait des enjeux d’oiseaux de l’aménagement écosystémique dans la réserve faunique des Laurentides. Study conducted by GENIVAR for the Canadian Wildlife Service of Environment Canada as part of a pilot project of the Ministère des Ressources naturelles et de la Faune. 114 p. + annexes.

Rodenhouse, N.L., S.N. Mathews, K.P. McFarland, J.D. Lambert, N.R. Iverson, A. Prassad, T.S. Sillett and R.T. Holmes. 2008. Potential effects of climate change on birds of the Northeast. Mitigation and Adaptation Strategies for Global Change 13:517-540.

Rompré, G., Y. Aubry, V. Connolly, J-P.L. Savard and G. Seutin. 1999 (unpublished). Répartition, abondance et préférences écologiques de la Grive de Bicknell (Catharus bicknelli) au Québec. Canadian Wildlife Service. 56 p.

Rousseu, F. and B. Drolet. 2015. Prediction of the nesting phenology of birds in Canada. In J. Hussell and D. Lepage. 2015. Bird Nesting Calendar Query Tool. Project NestWatch. Bird Studies Canada / Études d’Oiseaux Canada. [Accessed February 16, 2016].

Sabo, S.A.R. 1980. Niche and habitat relations in subalpine bird communities of the White Mountains of New Hampshire. Ecol. Monogr. 50:241-259.

Sanz, J.J., J. Potti, J. Moreno, S. Merino and O. Frias. 2003. Climate change and fitness components of a migratory bird breeding in the Mediterranean region. Global Change Biology 9:461-472.

Sergile, F.E. 2008. Haiti. Pages 193-204, in Important Bird Areas in the Caribbean: Key Sites for Conservation (D.A. Wege and V. Anadon-Irizarry, Eds.). BirdLife International, Cambridge, UK.

Sillett, T.S., R.T. Holmes and T.W. Sherry. 2000. Impacts of global climate cycle on population dynamics of a migratory songbird. Science 288:2040-2042.

Smith, C., K. Beazley, P. Duinker and K.A. Harper. 2010. The impact of moose (Alces alces andersoni) on forest regeneration following a severe spruce budworm outbreak in the Cape Breton highlands, Nova Scotia, Canada. Alces 46:135-150.

Sprugel, D.G. 1976. Dynamic structure of wave-regenerated Abies balsamea forests in the North-Eastern United States. Journal of Ecology 64(3):889-911.

Stattersfield, A.J., M.J. Crosby, A.J. Long and D.C. Wege. 1998. Endemic bird areas of the world: priorities for biodiversity conservation. Birdlife Conservation Series No. 7, BirdLife International, Cambridge, UK.

Townsend, J.M., C.C. Rimmer, J. Brocca, K.P. McFarland and A.K. Townsend. 2009. Predation of a wintering migratory songbird by introduced rats: can nocturnal roosting behavior serve as predator avoidance? Condor 111:565-569.

Townsend, J.M. 2011. Mercury accumulation in forest floor horizons, songbirds and salamanders along a forested elevational gradient in the Catskills Mountains, New York. Ph.D. thesis, State University of New York College of Environmental Science and Forestry, Syracuse, N.Y.

Townsend, J.M., C.C. Rimmer, A.T. Townsend and K.P. McFarland. 2011. Sex and age ratios of Bicknell’s Thrush wintering in Hispaniola. Wilson Journal of Ornithology 123:367-372.

Townsend, J.M., C.C. Rimmer, C.T. Driscoll, K.P. McFarland and E. Inigo-Elias. 2013. Mercury concentrations in tropical resident and migrant songbirds on Hispaniola. Ecotoxicology 22:86-93.

Wallace, G.J. 1939. Bicknell’s Thrush, Its Taxonomy, Distribution, and Life History. Proceedings of the Boston Society of Natural History 41:211-402.

Whittam, B. and M. Ball. 2003. High Elevation Landbird Program, 2002 Report. Unpublished report by Bird Studies Canada (Atlantic Region), Sackville, NB.

Wilson, M.D. and B.D. Watts. 1997. Autumn migration of Gray-cheeked and Bicknell’s thrushes at Kiptopeke, Virginia. Journal of Field Ornithology 68: 519-525.

Wormworth, J. and K. Mallon. 2006. Bird Species and Climate Change: The Global Status Report, Version 1.0 [Online]. Climate Risk Limited, Brisbane, Australia.

Zimmerling, J.R., A.C. Pomeroy, M.V. d'Entremont and C.M. Francis. 2013. Canadian Estimate of Bird Mortality Due to Collisions and Direct Habitat Loss Associated with Wind Turbine Developments. Avian Conservation and Ecology 8(2):10.

Appendix A: NatureServe conservation status rank definitions

The table below lists the conservation status ranks used by NatureServe and their definitions. These status ranks are appended to the letter “G” (global rank, applies to the entire range), “N” (national rank, applies on a national scale) or “S” (subnational rank, for a province or state). A numeric range rank (e.g., S1S2) is used to indicate uncertainty about the status of the species or community in question.

Rank table
RankDefinition
1Critically Imperiled – Species or community that is extremely rare (often five or fewer occurrences) or is affected by very steep declines or other factors that could result in its extirpation.
2Imperiled – Species or community that is rare because of its very restricted range, very few populations (often fewer than 20), steep population declines or other factors that could result in its extirpation.
3Vulnerable – Species or community with a very restricted range and relatively few populations (often 80 or fewer) that has experienced recent and widespread declines and is affected by other factors that could result in its extirpation.
4Apparently Secure – Species or community that is uncommon but not rare. There is some cause for long-term concern because of declines or other factors.
5Secure – Species or community that is common, widespread and abundant in the jurisdiction.
BBreeding – Conservation status refers to the breeding population of the species in the nation or state/province.
NNonbreeding – Conservation status refers to the non-breeding population of the species in the nation or state/province.
MMigrant – Migrant species occurring regularly on migration at particular migratory stopovers or staging areas where the species might warrant conservation attention. Conservation status refers to the aggregating transient population of the species in the nation or state/province.
NRSpecies or community that is unranked because its status has not yet been assessed.
NANot Applicable – The species or community is not a suitable target for conservation activities.
UUnassessed – Species not assessed due to a lack of information or substantially conflicting information about status or trends.
?Inexact or Uncertain – Denotes inexact or uncertain numeric rank.

Appendix B: Standard breeding bird atlas codes

Possible breeding
Atlas codedDescription
HSpecies observed in suitable nesting habitat during its breeding season.
SIndividual singing or producing other sounds associated with breeding (e.g., calls or drumming) in suitable nesting habitat during the species' breeding season.
Probable breeding
Atlas codedDescription
PPair observed in their breeding season in suitable nesting habitat
TPermanent territory presumed through registration of territorial behaviour (song, etc.), or the occurrence of an adult bird, on at least two days, a week or more apart, at the same place, in suitable nesting habitat during the breeding season.
DCourtship or display between a male and a female or two males including courtship, feeding or copulation.
VVisiting probable nest site.
AAgitated behaviour or anxiety calls of an adult indicating nest-site or young in the vicinity.
BBrood patch on adult female or cloacal protuberance on adult male.
Confirmed breeding
Atlas codedDescription
NBNest building or carrying nest materials.
DDDistraction display or injury feigning.
NUUsed nest or egg shells found (occupied or laid within the period of the survey). Use only for unique and unmistakable nests or shells
FYRecently fledged young or downy young.
AEAdults leaving or entering nest sites in circumstances indicating occupied nest (including nests the contents of which cannot be seen).
FSAdult carrying fecal sac.
CFAdult carrying food for young during its breeding season.
NENest containing eggs.
NYNest containing young seen or heard.

h Atlas codes and descriptions can vary slightly from one province to another but convey similar meanings. Atlas codes for possible breeding are not presented here.

Appendix C: Critical habitat for the Bicknell’s Thrush in Canada

Table C-1. Description of the 10 x 10 km Standardized UTM Grids and Critical Habitat Units for the Bicknell’s Thrush in Quebec. Critical habitat refers to areas where the criteria set out in section 7.1 are met.
10 x 10 km Standardized UTM Grid Square IDiUTM Grid Square Coordinatesj
Easting
UTM Grid Square Coordinates
Northing
Critical Habitat Unit Area (ha)kLand Tenurel
18VS46440000516000028Non-federal
18VS47440000517000099Non-federal
18VS5645000051600003093Non-federal
18VS5745000051700004675Non-federal
18WS215200005110000124Non-federal
18WS225200005120000703Non-federal
18WS3153000051100002818Non-federal
18WS3253000051200006001Non-federal
18WS41540000511000035Non-federal
18WS425400005120000189Non-federal
18WS4354000051300003216Non-federal
18WS4454000051400002649Non-federal
18WS5155000051100002776Non-federal
18WS5255000051200005808Non-federal
18WS5355000051300001899Non-federal
18WS5455000051400003789Non-federal
18WS62560000512000023Non-federal
18WS6356000051300001241Non-federal
18WS6456000051400004610Non-federal
18XQ8968000049900001481Non-federal
18XQ98690000498000051Non-federal
18XQ9969000049900007105Non-federal
18XR90690000500000071Non-federal
19CL213200005010000634Non-federal
19CL2332000050300002695Non-federal
19CL24320000504000076Non-federal
19CL3133000050100007519Non-federal
19CL3233000050200002295Non-federal
19CL3333000050300008863Non-federal
19CL343300005040000960Non-federal
19CL4134000050100003991Non-federal
19CL4234000050200006547Non-federal
19CL5135000050100009894Non-federal
19CL5235000050200004507Non-federal
19CL6236000050200003044Non-federal
19CL6336000050300002465Non-federal
19CL7237000050200004627Non-federal
19CL7337000050300005044Non-federal
19CL7537000050500003801Non-federal
19CL7637000050600002034Non-federal
19CL8538000050500001388Non-federal
19CL8638000050600003567Non-federal
19CL873800005070000681Non-federal
19CL9639000050600005589Non-federal
19CL9739000050700001396Non-federal
19CM753700005150000171Non-federal
19CM76370000516000076Non-federal
19CM8438000051400005Non-federal
19CM8538000051500009095Non-federal
19CM8638000051600007981Non-federal
19CM87380000517000077Non-federal
19CM9539000051500004191Non-federal
19CM9639000051600009043Non-federal
19CM9739000051700003941Non-federal
19CN0030000052000006Federal
19CN0130000052100007134Federal
19CN113100005210000738Non-federal
19CN1731000052700003167Non-federal
19CN1831000052800003599Non-federal
19CN233200005230000180Non-federal
19CN2432000052400001933Non-federal
19CN2532000052500002221Non-federal
19CN2632000052600007915Non-federal
19CN2732000052700006839Non-federal
19CN2832000052800003137Non-federal
19CN32330000522000048Non-federal
19CN3333000052300009266Non-federal
19CN3433000052400009643Non-federal
19CN3533000052500007422Non-federal
19CN3633000052600007749Non-federal
19CN3733000052700005484Non-federal
19CN3833000052800000Non-federal
19CN4334000052300004751Non-federal
19CN4434000052400009561Non-federal
19CN4534000052500006096Non-federal
19CN4634000052600002369Non-federal
19CN4734000052700003506Non-federal
19CN4834000052800007570Non-federal
19CN4934000052900002342Non-federal
19CN523500005220000132Non-federal
19CN5335000052300008738Non-federal
19CN5435000052400009998Non-federal
19CN5535000052500005633Non-federal
19CN5735000052700002833Non-federal
19CN5835000052800002466Non-federal
19CN5935000052900002432Non-federal
19CN6336000052300001129Non-federal
19CN6436000052400006917Non-federal
19CN6536000052500002978Non-federal
19CN6836000052800004503Non-federal
19CN6936000052900009151Non-federal
19CN7737000052700002694Non-federal
19CN7837000052800009790Non-federal
19CN79370000529000010000Non-federal
19CN873800005270000753Non-federal
19CN8838000052800001276Non-federal
19CN8938000052900005283Non-federal
19CN993900005290000219Non-federal
19CP1131000053100004859Federal
19CP123100005320000889Non-federal
19CP2132000053100003383Federal
19CP223200005320000200Non-federal
19CP303300005300000149Non-federal
19CP3133000053100008366Non-federal
19CP3233000053200001688Non-federal
19CP4034000053000004728Non-federal
19CP4134000053100008697Non-federal
19CP4234000053200003523Non-federal
19CP5035000053000002337Non-federal
19CP5135000053100001006Non-federal
19CP523500005320000291Non-federal
19CP583500005380000636Non-federal
19CP59350000539000030Non-federal
19CP6036000053000009761Non-federal
19CP6136000053100007730Non-federal
19CP673600005370000246Non-federal
19CP6836000053800009545Non-federal
19CP6936000053900002774Non-federal
19CP7037000053000003612Non-federal
19CP713700005310000490Non-federal
19CP7737000053700004697Non-federal
19CP7837000053800006788Federal
19CP793700005390000249Non-federal
19CP8038000053000006739Non-federal
19CP813800005310000228Non-federal
19CP823800005320000249Non-federal
19CP8738000053700003530Non-federal
19CP8838000053800004487Non-federal
19CP9039000053000004449Non-federal
19CP9139000053100006005Non-federal
19CP9239000053200006622Non-federal
19CP963900005360000180Non-federal
19CP9739000053700003867Non-federal
19CP9839000053800002383Non-federal
19CQ613600005410000775Non-federal
19CQ703700005400000491Non-federal
19CQ7137000054100006583Non-federal
19DM064000005160000576Non-federal
19DM074000005170000503Non-federal
19DP014000005310000556Non-federal
19DP0240000053200001818Non-federal
19DP0640000053600005024Non-federal
19DP0740000053700009748Non-federal
19DP0840000053800008965Non-federal
19DP1641000053600003648Non-federal
19DP1741000053700005101Non-federal
19DP1841000053800005267Non-federal
19DS9349000056300002518Non-federal
19DS944900005640000850Non-federal
19EP855800005350000339Non-federal
19EP8658000053600003388Non-federal
19EP955900005350000419Non-federal
19EP9659000053600004736Non-federal
19ER075000005570000138Non-federal
19ER0850000055800004228Non-federal
19ER17510000557000081Non-federal
19ER1851000055800003398Non-federal
19ES0350000056300003288Non-federal
19ES0450000056400001190Non-federal
19FP4964000053900002989Non-federal
19FP5965000053900003710Non-federal
19FP696600005390000114Non-federal
19FP9769000053700005084Non-federal
19FP9869000053800002092Non-federal
19FQ4064000054000002582Non-federal
19FQ5065000054000009746Non-federal
19FQ5165000054100001860Non-federal
19FQ6066000054000008458Non-federal
19FQ6166000054100007771Non-federal
19FQ626600005420000397Non-federal
19FQ7167000054100006886Non-federal
19FQ7267000054200001988Non-federal
19FQ8168000054100002382Non-federal
19FQ8268000054200008793Non-federal
19FQ83680000543000030Non-federal
19FQ9169000054100006205Non-federal
19FQ9269000054200009456Non-federal
19FQ93690000543000019Non-federal
19FS0160000056100008Non-federal
19FS0260000056200006459Non-federal
19FS0360000056300003258Non-federal
19FS1261000056200003001Non-federal
19FS136100005630000767Non-federal
19FT0160000057100004644Non-federal
19FT0260000057200002580Non-federal
19FT116100005710000466Non-federal
19FT126100005720000158Non-federal
19GP0770000053700004131Non-federal
19GP0870000053800004893Non-federal
19GP17710000537000062Non-federal
19GP187100005380000119Non-federal
19GQ00700000540000034Non-federal
19GQ0170000054100005002Non-federal
19GQ0270000054200008979Non-federal
19GQ10710000540000019Non-federal
19GQ1171000054100008075Non-federal
19GQ1271000054200008640Non-federal
19GQ1371000054300004711Non-federal
19GQ2072000053999994Non-federal
19GQ21720000541000095Non-federal
20KU9929000053900004791Non-federal
20KV70279330540000012Non-federal
20KV71279727541000094Non-federal
20KV8028000054000001013Non-federal
20KV8127999754100008229Non-federal
20KV8228011954200005669Non-federal
20KV8328051454300007542Non-federal
20KV8428090954399990Non-federal
20KV902900005400000149Non-federal
20KV9129000054100005544Non-federal
20KV9229000054200004588Non-federal
20KV9329000054300004324Non-federal
20KV9429000054400002Non-federal
20LU0930000053900002880Non-federal
20LV00300000540000037Non-federal
20LV0130000054100001599Non-federal
20LV0230000054200003949Non-federal
20LV0330000054300001448Non-federal
20LV0530000054500003689Non-federal
20LV1131000054100002850Non-federal
20LV12310000542000010007Non-federal
20LV1331000054300005851Non-federal
20LV1531000054500004153Non-federal
20LV21320000541000050Non-federal
20LV2232000054200005615Non-federal
20LV2332000054300001936Non-federal
20LV63360000543000026Non-federal
20LV7337000054300008480Non-federal
20LV743700005440000521Non-federal
20LV833800005430000804Non-federal
20MA78470000558000097Non-federal
20MA794700005590000116Non-federal
20MA8848000055800003699Non-federal
20MA8948000055900003966Non-federal
20MU06400000536000013Non-federal
20MU0740000053700006161Non-federal
20MU084000005380000542Non-federal
20MU1741000053700003236Federal
20MU18410000538000047Non-federal
20MV0040000054000005050Federal (Forillon National Park of Canada)
20MV0140000054100004606Federal (Forillon National Park of Canada)
20MV1041000054000003192Federal (Forillon National Park of Canada)
20MV114100005410000572Federal (Forillon National Park of Canada)

i The grid square ID is based on the standard UTM Military Grid Reference System, where the first two digits represent the UTM Zone, the following two letters indicate the 100 x 100 km standardized UTM grid, and the last two digits represent the 10 x 10 km standardized UTM grid containing all or a portion of the critical habitat unit. This unique alphanumeric code is based on the methodology used for the Breeding Bird Atlases of Canada (see web site for more information on breeding bird atlases).

j The listed coordinates are a cartographic representation of where critical habitat can be found, presented as the southwest corner of the 10 x 10 km standardized UTM grid containing all or a portion of the critical habitat. The coordinates may not fall within critical habitat and are provided as a general location only.

k The area presented is the sum of the area of critical habitat units within the UTM grid square (rounded up to the nearest 1 ha). It is an approximation obtained by drawing a 5 km radius around each observation meeting the habitat occupancy criteria (section 7.1.1). The exact area of critical habitat may be significantly less depending on where the criteria for critical habitat are met (see section 7.1). Field verification is required to determine the precise area of critical habitat.

l Land tenure is provided as an approximation of the types of land ownership that exist at the critical habitat units and should be used for guidance purposes only. Accurate land tenure will require cross referencing critical habitat boundaries with surveyed land parcel information.

Table C-2. Description of the 10 x 10 km Standardized UTM Grids and Critical Habitat Units for the Bicknell’s Thrush in New Brunswick. Critical habitat refers to areas where the criteria set out in section 7.1 are met.
10 x 10 km Standardized UTM Grid Square IDmUTM Grid Square Coordinatesn
Easting
UTM Grid Square Coordinatesn
Northing
Critical Habitat Unit Area (ha)oLand Tenurep
19EN465400005260000773Non-federal
19EN4754000052700003624Non-federal
19EN4954000052900002696Non-federal
19EN565500005260000643Non-federal
19EN5755000052700003517Non-federal
19EN58550000528000015Non-federal
19EN5955000052900008271Non-federal
19EN6856000052800001394Non-federal
19EN6956000052900007892Non-federal
19EN775700005270000726Non-federal
19EN7857000052800009351Non-federal
19EN7957000052900008281Non-federal
19EN875800005270000101Non-federal
19EN8858000052800002852Non-federal
19EN8958000052900009771Non-federal
19EN985900005280000827Non-federal
19EN9959000052900008570Non-federal
19EP40540000530000035Non-federal
19EP5055000053000005671Non-federal
19EP6056000053000005105Non-federal
19EP7057000053000005035Non-federal
19EP8058000053000009890Non-federal
19EP8158000053100001655Non-federal
19EP9059000053000005387Non-federal
19EP9159000053100007151Non-federal
19FK7467000049400002842Federal
19FK7567000049500001663Federal
19FK84680000494000021Non-federal
19FN0960000052900001351Non-federal
19FN2862000052800002Non-federal
19FN31630000521000068Non-federal
19FN326300005220000316Non-federal
19FN37630000527000054Non-federal
19FN3863000052800007790Non-federal
19FN4164000052100002483Non-federal
19FN4264000052200004980Non-federal
19FN536500005230000202Non-federal
19FN5465000052400005055Non-federal
19FN5565000052500005562Non-federal
19FN56650000526000029Non-federal
19FN6166000052100001878Non-federal
19FN6266000052200005944Non-federal
19FN6366000052300007057Non-federal
19FN6466000052400009106Non-federal
19FN6566000052500007537Non-federal
19FN6666000052600008330Non-federal
19FN6766000052700002961Non-federal
19FN7167000052100005359Non-federal
19FN7267000052200001000Non-federal
19FN7367000052300001000Non-federal
19FN7467000052400007806Non-federal
19FN75670000525000030Non-federal
19FN766700005260000719Non-federal
19FN776700005270000402Non-federal
19FN8168000052100002319Non-federal
19FN8268000052200007247Non-federal
19FN8368000052300001000Non-federal
19FN8468000052400009983Non-federal
19FN8568000052500002182Non-federal
19FN8668000052600001038Non-federal
19FN9269000052200001233Non-federal
19FN9369000052300003905Non-federal
19FN9469000052400002322Non-federal
19FN9569000052500005931Non-federal
19FN9669000052600006447Non-federal
19FP0060000053000002076Non-federal
19FP0160000053100004732Non-federal
20LR133100005030000649Non-federal
20LR143100005040000147Non-federal
20LR2332000050300001984Non-federal
20LR2432000050400002019Non-federal

m The grid square ID is based on the standard UTM Military Grid Reference System, where the first two digits represent the UTM Zone, the following two letters indicate the 100 x 100 km standardized UTM grid, and the last two digits represent the 10 x 10 km standardized UTM grid containing all or a portion of the critical habitat unit. This unique alphanumeric code is based on the methodology used for the Breeding Bird Atlases of Canada (see more information on breeding bird atlases).

n The listed coordinates are a cartographic representation of where critical habitat can be found, presented as the southwest corner of the 10 x 10 km standardized UTM grid containing all or a portion of the critical habitat. The coordinates may not fall within critical habitat and are provided as a general location only.

o The area presented is the sum of the area of critical habitat units within the UTM grid square (rounded up to the nearest 1 ha). It is an approximation obtained by drawing a 5 km radius around each observation meeting the habitat occupancy criteria (section 7.1.1). The exact area of critical habitat may be significantly less depending on where the criteria for critical habitat are met (see section 7.1). Field verification is required to determine the precise area of critical habitat.

p Land tenure is provided as an approximation of the types of land ownership that exist at the critical habitat units and should be used for guidance purposes only. Accurate land tenure will require cross referencing critical habitat boundaries with surveyed land parcel information.

Table C-3. Description of the 10 x 10 km Standardized UTM Grids and Critical Habitat Units for the Bicknell’s Thrush in Nova Scotia. Critical habitat refers to areas where the criteria set out in section 7.1 are met.
10 x 10 km Standardized UTM Grid Square IDqUTM Grid Square Coordinatesr
Easting
UTM Grid Square Coordinatesr
Northing
Critical Habitat Unit Area (ha)sLand Tenuret
20PS5565000051500001335Non-federal
20PS5665000051600003562Federal (Cape Breton Highlands National Park of Canada)
20PS5765000051700001769Federal (Cape Breton Highlands National Park of Canada)
20PS58650000518000033Federal (Cape Breton Highlands National Park of Canada)
20PS62660000512000013Non-federal
20PS6366000051300003978Non-federal
20PS6466000051400008656Non-federal
20PS6566000051500006222Non-federal
20PS6666000051600009308Federal (Cape Breton Highlands National Park of Canada)
20PS6766000051700009156Federal (Cape Breton Highlands National Park of Canada)
20PS6866000051800006192Federal (Cape Breton Highlands National Park of Canada)
20PS7267000051200004147Non-federal
20PS7367000051300007470Non-federal
20PS7467000051400009925Non-federal
20PS7567000051500009383Non-federal
20PS7667000051600008674Federal (Cape Breton Highlands National Park of Canada)
20PS7767000051700001814Federal (Cape Breton Highlands National Park of Canada)
20PS786700005180000393Federal (Cape Breton Highlands National Park of Canada)
20PS8468000051400002085Non-federal
20PS856800005150000423Non-federal
20PS8668000051600004671Federal (Cape Breton Highlands National Park of Canada)
20PS8768000051700008139Federal (Cape Breton Highlands National Park of Canada)
20PS8868000051800003440Federal (Cape Breton Highlands National Park of Canada)
20PS896800005190000354Federal (Cape Breton Highlands National Park of Canada)
20PS9769000051700003628Federal (Cape Breton Highlands National Park of Canada)
20PS9869000051800007820Federal (Cape Breton Highlands National Park of Canada)
20PS9969000051900002631Federal (Cape Breton Highlands National Park of Canada)
20PT806800005200000345Non-federal
20PT9069000052000004305Federal
20PT916900005210000905Federal
20QT1271000052200004Federal
20QT137100005230000502Federal

q The grid square ID is based on the standard UTM Military Grid Reference System, where the first two digits represent the UTM Zone, the following two letters indicate the 100 x 100 km standardized UTM grid, and the last two digits represent the 10 x 10 km standardized UTM grid containing all or a portion of the critical habitat unit. This unique alphanumeric code is based on the methodology used for the Breeding Bird Atlases of Canada (see more information on breeding bird atlases).

r The listed coordinates are a cartographic representation of where critical habitat can be found, presented as the southwest corner of the 10 x 10 km standardized UTM grid containing all or a portion of the critical habitat. The coordinates may not fall within critical habitat and are provided as a general location only.

s The area presented is the sum of the area of critical habitat units within the UTM grid square (rounded up to the nearest 1 ha). It is an approximation obtained by drawing a 5 km radius around each observation meeting the habitat occupancy criteria (section 7.1.1). The exact area of critical habitat may be significantly less depending on where the criteria for critical habitat are met (see section 7.1). Field verification is required to determine the precise area of critical habitat.

t Land tenure is provided as an approximation of the types of land ownership that exist at the critical habitat units and should be used for guidance purposes only. Accurate land tenure will require cross referencing critical habitat boundaries with surveyed land parcel information.

Figure C-1. Critical habitat for the Bicknell’s Thrush in the administrative region of Bas-Saint-Laurent, Quebec. Critical habitat is represented by the shaded yellow polygon (unit), where the critical habitat identification criteria and method set out in section 7.1 are met. The 10 x 10 km UTM grid overlay (in red) is a standardized national grid system that indicates the general geographic location of the critical habitat.
Map of C1 (see long description below)
Long description for Figure C1

Figure C-1 shows the critical habitat for the Bicknell’s Thrush in the administrative region of Bas-Saint-Laurent, Quebec using 10 km x 10 km standardized grid overlay. The critical habitat is in accordance with the criteria and methodology set out in section 7.1. There are 4 UTM grid squares east of Rimouski.

Figure C-2. Critical habitat for the Bicknell’s Thrush in the administrative region of Saguenay – Lac Saint-Jean, Quebec. Critical habitat is represented by the shaded yellow polygon (unit), where the critical habitat identification criteria and method set out in section 7.1 are met. The 10 x 10 km UTM grid overlay (in red) is a standardized national grid system that indicates the general geographic location of the critical habitat.
Map of C2 (see long description below)
Long description for Figure C2

Figure C-2 shows the critical habitat for the Bicknell’s Thrush in the administrative region of Saguenay – Lac Saint-Jean, Quebec using 10 km x 10 km standardized grid overlay. The critical habitat is in accordance with the criteria and methodology set out in section 7.1. There are 22 UTM grid squares ranging north of the Fjord du Saguenay east from Saint-Ambroise to north-west of Sacré Coeur.

Figure C-3. Critical habitat for the Bicknell’s Thrush in the administrative region of Capitale-Nationale, Quebec. Critical habitat is represented by the shaded yellow polygon (unit), where the critical habitat identification criteria and method set out in section 7.1 are met. The 10 x 10 km UTM grid overlay (in red) is a standardized national grid system that indicates the general geographic location of the critical habitat.
Map of C3 (see long description below)
Long description for Figure C3

Figure C-3 shows the critical habitat for the Bicknell’s Thrush in the administrative region of Capitale Nationale, Quebec using 10 km x 10 km standardized grid overlay. The critical habitat is in accordance with the criteria and methodologies set out in section 7.1.There are 68 UTM grid squares ranging west of the Saint-Lawrence River from Saint Simeon to Saint- Anne-de-Beaupré.

Figure C-4. Critical habitat for the Bicknell’s Thrush in the administrative regions of Estrie and Chaudière-Appalaches, Quebec. Critical habitat is represented by the shaded yellow polygon (unit), where the critical habitat identification criteria and method set out in section 7.1 are met. The 10 x 10 km UTM grid overlay (in red) is a standardized national grid system that indicates the general geographic location of the critical habitat.
Map of C4 (see long description below)
Long description for Figure C4

Figure C-4 shows the critical habitat for the Bicknell’s Thrush in the administrative regions of Estrie and Chaudière-Appalaches, Quebec using 10 km x 10 km standardized grid overlay. The critical habitat is in accordance with the criteria and methodology set out in section 7.1. There are 11 UTM grid squares east of Sainte-Claire ranging down to Lac Etchemin. There are 7 more UTM grid squares south of Saint-Martin ranging to northeast of Lac-Mégantic as well as 15 more UTM grid squares in the southwestern region by Lac-Mégantic. The last section squares consists of 3 UTM grid squares just south of Cowansville.

Figure C-5. Critical habitat for the Bicknell’s Thrush in the administrative region of Côte-Nord, Quebec. Critical habitat is represented by the shaded yellow polygon (unit), where the critical habitat identification criteria and method set out in section 7.1 are met. The 10 x 10 km UTM grid overlay (in red) is a standardized national grid system that indicates the general geographic location of the critical habitat.
Map of C5 (see long description below)
Long description for Figure C5

Figure C-5 shows the critical habitat for the Bicknell’s Thrush in the administrative region of Côte-Nord, Quebec using 10 km x 10 km standardized grid overlay. The critical habitat is in accordance with the criteria and methodology set out in section 7.1. There are 4 UTM grid squares located in the central region of Monts Groulx with 5 more UTM grid squares located south of the previously mentioned. There are 4 more UTM grid squares in the Réservoir Outardes Quatre region and 4 more UTM grid squares just northeast of the grids previously mentioned and south of Île René Levasseur.

Figure C-6. Critical habitat for the Bicknell’s Thrush in the administrative region of Côte-Nord, Quebec. Critical habitat is represented by the shaded yellow polygon (unit), where the critical habitat identification criteria and method set out in section 7.1 are met. The 10 x 10 km UTM grid overlay (in red) is a standardized national grid system that indicates the general geographic location of the critical habitat.
Map of C6 (see long description below)
Long description for Figure C6

Figure C-6 shows the critical habitat for the Bicknell’s Thrush in the administrative region of Côte-Nord, Quebec using 10 km x 10 km standardized grid overlay. The critical habitat is in accordance with the criteria and methodology set out in section 7.1. There are 4 UTM grid squares located in the region of the Mingan Archipelago National Park Reserve.

Figure C-7. Critical habitat for the Bicknell’s Thrush in the administrative region of Gaspésie – Îles-de-la-Madeleine, Quebec. Critical habitat is represented by the shaded yellow polygon (unit), where the critical habitat identification criteria and method set out in section 7.1 are met. The 10 x 10 km UTM grid overlay (in red) is a standardized national grid system that indicates the general geographic location of the critical habitat.
Map of C7 (see long description below)
Long description for Figure C7

Figure C-7 shows the critical habitat for the Bicknell’s Thrush in the administrative region of Gaspésie – Îles-de-la-Madeleine, Quebec using 10 km x 10 km standardized grid overlay. The critical habitat is in accordance with the criteria and methodology set out in section 7.1. There are 48 UTM grid squares that span across the Monts Notre-Dame region just east of Sainte-Félicité bordering the Saint-Lawrence River. There are 4 more UTM grid squares in the Monts Berry region.

Figure C-8. Critical habitat for the Bicknell’s Thrush in the administrative region of Gaspésie – Îles-de-la-Madeleine, Quebec. Critical habitat is represented by the shaded yellow polygon (unit), where the critical habitat identification criteria and method set out in section 7.1 are met. The 10 x 10 km UTM grid overlay (in red) is a standardized national grid system that indicates the general geographic location of the critical habitat.
Map of C8 (see long description below)
Long description for Figure C8

Figure C-8 shows the critical habitat for the Bicknell’s Thrush in the administrative region of Gaspésie – Îles-de-la-Madeleine, Quebec using 10 km x 10 km standardized grid overlay. The critical habitat is in accordance with the criteria and methodology set out in section 7.1. There are 5 UTM grid squares just north-east of Grande-Rivière with 4 more squares just north of those mentioned in between the Baie de Gaspé and Forillon National Park. There are 3 more UTM grid squares just north-west Forillon National Park.

Figure C-9. Critical habitat for the Bicknell’s Thrush in the administrative region of Laurentides, Quebec. Critical habitat is represented by the shaded yellow polygon (unit), where the critical habitat identification criteria and method set out in section 7.1 are met. The 10 x 10 km UTM grid overlay (in red) is a standardized national grid system that indicates the general geographic location of the critical habitat.
Map of C9 (see long description below)
Long description for Figure C9

FigureC-9 shows the critical habitat for the Bicknell’s Thrush in the administrative region of Laurentides, Quebec using 10 km x 10 km standardized grid overlay. The critical habitat is in accordance with the criteria and methodology set out in section 7.1. There are 15 UTM grid squares that range within the region of Parc National du Mont Tremblant until Labelle. There are 4 more grid squares west of Femme-Neuve and north of Mont-Laurier.

Figure C-10. Critical habitat for the Bicknell’s Thrush in northern New Brunswick. Critical habitat is represented by the shaded yellow polygon (unit), where the critical habitat identification criteria and method set out in section 7.1 are met. The 10 x 10 km UTM grid overlay (in red) is a standardized national grid system that indicates the general geographic location of the critical habitat.
Map of C10 (see long description below)
Long description for Figure C10

Figure C-10 shows the critical habitat for the Bicknell’s Thrush in northern New Brunswick and part of Quebec using 10 km x 10 km standardized grid overlay. The critical habitat is in accordance with the criteria and methodology set out in section 7.1. There are 33 UTM grid squares expanding from the region of Mount Carleton Provincial Park. There are 3 more UTM grid near Kedgwick, NB and 28 more grid squares which range across the borders of Quebec and New Brunswick just north of Edmundston to just west of Kedgwick.

Figure C-11. Critical habitat for the Bicknell’s Thrush in southern New Brunswick. Critical habitat is represented by the shaded yellow polygon (unit), where the critical habitat identification criteria and method set out in section 7.1 are met. The 10 x 10 km UTM grid overlay (in red) is a standardized national grid system that indicates the general geographic location of the critical habitat.
Map of C11 (see long description below)
Long description for Figure C11

Figure C-11 shows the critical habitat for the Bicknell’s Thrush in southern New Brunswick using 10 km x 10 km standardized grid overlay. The critical habitat is in accordance with the criteria and methodology set out in section 7.1. There are 3 UTM grid squares in the region of Manan. There are 4 more UTM grid squares east of the south-most point of the Kensington Peninsula.

Figure C-12. Critical habitat for the Bicknell’s Thrush in Nova Scotia. Critical habitat is represented by the shaded yellow polygon (unit), where the critical habitat identification criteria and method set out in section 7.1 are met. The 10 x 10 km UTM grid overlay (in red) is a standardized national grid system that indicates the general geographic location of the critical habitat.
Map of C12 (see long description below)
Long description for Figure C12

Figure C-12 shows the critical habitat for the Bicknell’s Thrush in Nova Scotia using 10 km x 10 km standardized grid overlay. The critical habitat is in accordance with the criteria and methodology set out in section 7.1. There are 35 UTM grid squares that encompass the majority of Cape Breton Island and span up to the Cape Breton highlands including 7 grid squares reaching into the Cabot Strait waters.

Appendix D: Effects on the environment and other species

A strategic environmental assessment (SEA) is conducted on all SARA recovery planning documents, in accordance with the Cabinet Directive on the Environmental Assessment of Policy, Plan and Program Proposals. The purpose of a SEA is to incorporate environmental considerations into the development of public policies, plans and program proposals to support environmentally sound decision-making and to evaluate whether the outcomes of a recovery planning document could affect any component of the environment or any of the Federal Sustainable Development Strategy’s (FSDS) goals and targets.

Recovery planning is intended to benefit species at risk and biodiversity in general. However, it is recognized that strategies may also inadvertently lead to environmental effects beyond the intended benefits. The planning process based on national guidelines directly incorporates consideration of all environmental effects, with a particular focus on possible impacts on non-target species or habitats. The results of the SEA are incorporated directly into the strategy itself, but are also summarized below in this statement.

The broad recovery strategies proposed for the Bicknell’s Thrush could also benefit other bird species that breed in habitats similar to those used by the Bicknell’s Thrush and that are likewise at risk in Canada, including the Olive-sided Flycatcher (Contopus cooperi), Canada Warbler (Cardellina canadensis) and Barrow’s Goldeneye (Bucephala islandica). In addition, the conservation measures taken for the Bicknell’s Thrush in its wintering area will benefit a number of other bird species at risk (as per the IUCN criteria) that are present in the wintering area: the Black-capped Petrel (Pterodroma hasitata) (endangered), Plain Pigeon (Patagioenas inornata) (near threatened), White-fronted Quail-dove (Geotrygon leucometopia) (vulnerable), Hispaniolan Parakeet (Aratinga chloroptera) (vulnerable), Hispaniolan Amazon (Amazona ventralis) (vulnerable), Hispaniolan Trogon (Priotelus roseigaster) (near threatened), La Selle Thrush (Turdus swalesi) (endangered), White-winged Warbler (Xenoligea montana) (vulnerable), Gray-crowned Palm Tanager (Phaenicophilus poliocephalus) (near threatened), Eastern Chat-tanager (Calyptophilus frugivorus) (vulnerable), Western Chat-tanager (Calyptophilus tertius) (vulnerable), Hispaniolan Crossbill (Loxia megaplaga) (endangered), White-crowned Pigeon (Patagioenas leucocephala) (near threatened) and Cuban Solitaire (Myadestes elisabeth) (near threatened) (IBTCG 2010).

Mammals that use habitats near those of the Bicknell’s Thrush include the Woodland Caribou (Rangifer tarandus caribou), Gaspésie-Atlantic population (endangered) and the Woodland Caribou (Rangifer tarandus caribou), boreal population (threatened). The recovery measures developed for the Bicknell’s Thrush will also be beneficial for them.

Another important broad strategy for recovery presented in this recovery strategy involves the conservation, stewardship and management of known and potential Bicknell’s Thrush wintering habitats (which are outside of Canada). In addition, the restoration of these habitats, which now cover only a fraction of the area historically covered, will likely benefit the overall biodiversity of this region. It is therefore reasonable to think that this recovery strategy will not result in significant adverse effects on the environment or other species in the Bicknell’s Thrush wintering area.

Footnotes

Footnote 1

The “biological” area of occupancy is the total area of habitat occupied by all existing populations. For a species of bird, the number of pairs and the average home range can be estimated; the area of occupancy can be roughly estimated by multiplying the two values (COSEWIC. 2013. Instructions for the Preparation of COSEWIC Status Reports. Committee on the Status of Endangered Wildlife in Canada. Ottawa. 30 p.

Return to footnote 1 referrer

Footnote 2

This document uses the expression “managed” forest rather than “industrial” forest, which was used in the COSEWIC Status Report on Bicknell’s Thrush (Catharus bicknelli) in Canada (COSEWIC 2009). It better describes the reality and uses.

Return to footnote 2 referrer

Footnote 3

Breeding Bird Survey Results.

Return to footnote 3 referrer

Footnote 4

Thickets of stunted, twisted spruce and fir that grow along the coast

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Footnote 5

Pre-commercial thinning is a partial tree harvest in an immature stand to create more space for the remaining trees in order to accelerate diameter growth, and also, through proper selection, to improve their general shape. The harvested trees have no commercial value and are generally left on site.

Return to footnote 5 referrer

Footnote 6

Planting is designed to regenerate a previously harvested area by planting an appropriate species to obtain optimal density.

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Footnote 7

The “biological” area of occupancy is the total area of habitat occupied by all existing populations. For a species of bird, the number of pairs and the average home range can be estimated; the area of occupancy can be roughly estimated by multiplying the two values (COSEWIC 2013).

Return to footnote 7 referrer

Footnote 8

The area included in a polygon without concave angles that encompasses the geographic distribution of all known populations of a species (COSEWIC 2013).

Return to footnote 8 referrer

Footnote 9

The landscape approach is based on landscape ecology. With this approach, it is possible to work at a broader scale and to integrate the various spatial-temporal components of the territory studied--i.e., biological, geographical, physical, socio-economic and heritage components--into the analyses.

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Footnote 10

Immature tree whose stem is still relatively flexible with a dbh of over 1 cm and less than 9 cm (MRN, 2013)

Return to footnote 10 referrer