Caribou (Rangifer tarandus) COSEWIC assessment and status report 2014: chapter 1

Section 1

Document Information

COSEWIC Logo and Wordmark

COSEWIC. 2014. COSEWIC assessment and status report on the Caribou Rangifer tarandus, Northern Mountain population, Central Mountain population and Southern Mountain population in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. xxii + 113 pp. (Species at Risk Public Registry).

Previous report(s):

COSEWIC. 2002. COSEWIC assessment and update status report on the woodland caribou Rangifer tarandus caribou in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. xi + 98 pp. (Species at Risk Public Registry)

Thomas, D.C., and D.R. Gray. 2002. Update COSEWIC status report on the woodland caribou Rangifer tarandus caribou in Canada, in COSEWIC assessment and update status report on the Woodland Caribou Rangifer tarandus caribou in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. 1-98 pp.

Kelsall, J.P. 1984. COSEWIC status report on the woodland caribou Rangifer tarandus caribou in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. 103 pp.

Production note:

COSEWIC would like to acknowledge Deborah Cichowski for writing the status report on Caribou Rangifer tarandus, Northern Mountain population, Central Mountain population and Southern Mountain population in Canada, prepared under contract with Environment Canada. This status report was overseen and edited by Justina Ray, Co-chair of the COSEWIC Terrestrial Mammals Specialist Subcommittee.

For additional copies contact:

COSEWIC Secretariat
c/o Canadian Wildlife Service
Environment Canada
Ottawa, ON
K1A 0H3

Tel.: 819-953-3215
Fax: 819-994-3684
COSEWIC E-mail
COSEWIC web site

Également disponible en français sous le titre Ếvaluation et Rapport de situation du COSEPAC sur le Caribou (Rangifer tarandus), population des montagnes du Nord, population des montagnes du Centre et population des montagnes du Sud au Canada.

Cover illustration/photo:
Caribou -- Photo of a Caribou from the Central Mountain population, Kennedy Siding subpopulation. Photo credit: Dayn Craig (with permission).

©Her Majesty the Queen in Right of Canada, 2014.

Catalogue No. CW69-14/697-2014E-PDF
ISBN 978-1-100-23963-7

COSEWIC logo

COSEWIC Assessment Summary

Assessment Summary - May 2014

Common name
Caribou - Northern Mountain population
Scientific name
Rangifer tarandus
Status
Special Concern
Reason for designation
This population occurs in 45 subpopulations ranging from west-central British Columbia to the Yukon and western Northwest Territories. Almost all of its distribution is in Canada, where it numbers about 43,000 - 48,000 mature individuals. There is little long-term (three generations) trend information, and many current estimates are based on survey data more than 5 years old. Currently 2 subpopulations are thought to be increasing, 7 are stable and 9 are declining. The condition of the remaining 27 subpopulations is unknown. The two largest subpopulations comprise > 15,000 animals, or 26-29% of the estimated population, and are thought to be stable. About half of the 45 subpopulations each contain < 500 individuals. All stable or increasing subpopulations are located in the northern part of the range, whereas 9 in the southern part of the range have declined by 27% since the last assessment. The status of northern subpopulations may be compromised in the future because of increasing threats, particularly land use change with industrial development causing shifts in predator-prey dynamics.
Occurrence
Yukon, Northwest Territories, British Columbia
Status history
The Northern Mountain population was designated Not at Risk in May 2000. This population was formerly designated as part of the “Western population”(now de-activated). Status re-examined and designated Special Concern in May 2002. Following the Designatable Unit report on caribou (COSEWIC 2011), a new population structure was proposed and accepted by COSEWIC. This new Northern Mountain population is composed of all 36 subpopulations in the previous Northern Mountain population of Caribou in addition to 9 subpopulations from the previous (2002) Southern Mountain population. The Northern Mountain population was designated Special Concern in May 2014.

Assessment Summary - May 2014

Common name
Caribou - Central Mountain population
Scientific name
Rangifer tarandus
Status
Endangered
Reason for designation
This population is endemic to Canada and occurs in 10 extant subpopulations in east-central British Columbia and west-central Alberta in and around the Rocky Mountains. The current estimate for the population is 469 mature individuals and it has declined by at least 64% over the past 3 generations. One subpopulation in central British Columbia was confirmed extirpated in 2014, and an additional one in Banff in 2010. All extant subpopulations are estimated to contain fewer than 250 mature individuals, with 4 of these having fewer than 50. Two recognized subpopulations in 2002 have since split due to lack of dispersal within former ranges. All subpopulations have experienced declines of about 60% since the last assessment in 2002, and declines continue for all but one subpopulation, which has an unknown trend. Surveys have shown consistently high adult mortality and low calf recruitment, accelerating decline rates. Threats are continuing and escalating.
Occurrence
British Columbia, Alberta
Status history
Following the Designatable Unit report on caribou (COSEWIC 2011), a new population structure was proposed and accepted by COSEWIC. This resulted in the new Central Mountain population, composed of 12 subpopulations from the previous Southern Mountain population of Caribou (COSEWIC 2002). The Central Mountain population was designated Endangered in May 2014.

Assessment Summary - May 2014

Common name
Caribou - Southern Mountain population
Scientific name
Rangifer tarandus
Status
Endangered
Reason for designation
This population is largely restricted to Canada, except for < 40 animals in Idaho and Washington. It occurs in 15 extant subpopulations in southeastern British Columbia. Two subpopulations have been extirpated since 2002. The current estimate for the population is 1,356 mature individuals, which has declined by at least 45% in the past three generations, and 27% since the last assessment in 2002. All but two extant subpopulations are estimated to contain fewer than 250 mature individuals, with 9 of these having fewer than 50, and 6 with fewer than 15 mature individuals. Dispersal within the ranges of 11 subpopulations is severely limited. Surveys have shown consistently high adult mortality and low calf recruitment, accelerating decline rates. Threats are continuing and escalating.
Occurrence
British Columbia
Status history
The Southern Mountain population was designated Threatened in May 2000. This population was formerly designated as part of the “Western population” (now deactivated). Status re-examined and confirmed in May 2002. Following the Designatable Unit report on Caribou (COSEWIC 2011), a new population structure was proposed and accepted by COSEWIC. This resulted in the new Southern Mountain population, composed of 17 subpopulations from the former Southern Mountain population of Caribou (COSEWIC 2002). The remaining subpopulations were assigned to the new Central and Northern Mountain populations.The Southern Mountain population was designated Endangered in May 2014.

COSEWIC Executive Summary

Caribou
Rangifer tarandus

Northern Mountain population
Central Mountain population
Southern Mountain population

Wildlife Species Description and Significance

All the world’s caribou and reindeer belong to a single species, Rangifer tarandus, and are found in arctic and subarctic regions as well as in northern forests. Caribou that occur in the western mountainous region of Canada are largely brown in colour with a white mane. Mature females and males usually weigh 110-150 kg and 160-210 kg, respectively. Both males and females grow antlers, although some females may lack these. A distinctive characteristic is large, rounded hooves that reduce sinking in snow and wetlands and act as shovels when digging for food under snow.

Western mountain caribou have played an important role for Aboriginal peoples as well as for early fur traders and settlers. A majority of the current range is in Canada in the Northern Mountain, Central Mountain and Southern Mountain populations. Northern and Central Mountain Caribou both inhabit shallow snow areas in winter where they forage primarily for terrestrial lichens, but differ in their genetic makeup and evolutionary origin. Southern Mountain Caribou are distinct from other mountain caribou in that they have adapted to living in a deep snow environment where they forage primarily for arboreal lichens in winter.

Distribution

Northern Mountain Caribou are currently distributed across 45 subpopulations ranging from west-central British Columbia north to Yukon and Northwest Territories. The Central Mountain population includes 10 extant subpopulations in east-central BC and west-central Alberta in and around the Rocky Mountains. Southern Mountain Caribou are distributed across 15 extant subpopulations in the deep snow-belt region of southeastern BC, and northern Idaho and Washington in the United States. There has been an overall range loss in western mountain caribou of about 30% since the early 1900s, with the major change in distribution occurring in the central and southern portion of BC and Alberta.

Habitat

In general, caribou require large tracts of range where they can separate themselves (horizontally and altitudinally) from other prey and predators, and shift their range use in response to various natural processes (e.g. fire, forest insects, weather/snow conditions) and human activities (e.g. disturbance from forest harvesting, mining, oil and gas, and recreation). Access to high-quality undisturbed calving areas in high-elevation alpine, subalpine parkland, subalpine forests, and/or islands in lakes is also essential to mountain caribou survival. While some subpopulations or portions of subpopulations migrate long distances between winter and summer ranges, others do not.

In winter months, both Northern and Central Mountain Caribou forage primarily on terrestrial lichens either in older coniferous forests at low elevations or on windswept alpine slopes, and summer at high elevations in mountains. They also may forage on arboreal lichens in older low-elevation and subalpine forests. Southern Mountain Caribou spend the winter at higher elevations in older subalpine forests where they are able to walk on a hardened snowpack and eat arboreal lichens. Caribou habitat has declined in quality and extent on many ranges due to impacts from industrial activities, particularly in Alberta and British Columbia.

Biology

Mountain caribou breed in late September and October. Mountain caribou have only one calf per year and females do not generally breed until they are at least 2 years old. Although pregnancy rates are generally high (over 90%), calf survival during the first few months is often 50% or less. Pregnant females travel to isolated, relatively predator-free areas in the mountains to calve in mid-late May or early June. Calf survival is higher for females that calve at high elevations in mountainous terrain or on islands in lakes, compared to females that calve below treeline where they are closer to other ungulates and predators. Caribou are usually one of several prey species in multiple predator-prey systems. Wolves and bears are the main predators of caribou; however, cougars, wolverine, golden eagles, and other predators may also kill adults and/or calves in some areas or during some seasons. Although they have diverse diets, western mountain caribou are adapted to feed on lichens, with specialized microbes in their stomachs that digest and extract nutrients from lichens efficiently. They can withstand severe cold because their thick winter coat contains insulating semi-hollow hair.

Population Sizes and Trends

The current Northern Mountain Caribou population estimate is about 45 000 mature individuals; however, estimates for only 16 of 45 (36%) of the subpopulations are based on surveys conducted within the last 5 years. Twenty-six subpopulations consist of >500 caribou and 13 are <250. Current trends are known for 18 subpopulations: 9 decreasing, 7 stable, and 2 increasing; all 5 subpopulations in west-central BC are declining. Late winter calf recruitment was <15% for 6 of 10 subpopulations with sufficient data. An overall trend for caribou in the Northern Mountain DU is not possible to determine because survey data and/or data on vital rates for most subpopulations are lacking. The 9 subpopulations in the southern part of the range have declined by 27% since the last COSEWIC assessment in 2002.

The current Central Mountain DU caribou population is estimated at 469 mature individuals. The population has declined by at least 64% over the last 27 years (3 generations) and 62% over the last 18 years (2 generations). All 10 currently recognized extant subpopulations consist of <250 mature individuals; 4 of these are <50. All but one are in continued decline; the status of one is unknown. Two additional subpopulations have been confirmed extirpated since the last status report in 2002 and two recognized subpopulations in 2002 have since split into several due to lack of dispersal within some part of the ranges.

The current estimate for the Southern Mountain DU caribou population is 1,356 mature individuals. The population has declined by at least 45% over the last 27 years (3 generations), 40% over the last 18 years (2 generations), and 27% since the last assessment in 2002. All 15 extant subpopulations consist of <500 mature individuals, 13 of which are <250, and 9 <50; some former subpopulations have split into several due to lack of dispersal within ranges. Fourteen of 15 subpopulations have declined since the last status report in 2002. At present, 11 subpopulations are still declining, 3 are stable and 1 is increasing. Most subpopulations have been subjected to intensive management measures, including translocations, wolf sterilization programs, and moose reduction through liberalized hunting. Two additional subpopulations have been extirpated since 2002. A recent population viability analysis predicted that 13 of 15 subpopulations would be lost within 50 years.

Threats and Limiting Factors

In the Northern Mountain DU, major threats include altered predator-prey dynamics due to habitat change. Human disturbance and habitat loss (including functional habitat loss due to avoidance) have resulted from the cumulative effects of forest harvesting, mineral exploration and development and associated access, motorized and non-motorized recreational activities, changes in forest structure due to Mountain Pine Beetle infestations and/or associated salvage logging, and impacts from climate change.

The primary threats to caribou in the Central Mountain DU include altered predator-prey dynamics due to both direct and functional habitat loss and disturbance resulting from multiple industrial activities including forest harvesting, coal exploration and development, and oil and gas exploration and development. Additional factors include vehicle collisions, motorized recreation (all terrain vehicle, snowmobiling), facilitated access to caribou winter range for predators resulting from increased linear corridors and packed trails or ploughed roads in winter, impacts from climate change, and stochastic environmental events associated with small population sizes.

The primary threats to caribou in the Southern Mountain DU include altered predator/prey dynamics due to habitat change resulting from forest harvesting in adjacent low-elevation valley bottoms, snowmobiling, heli-skiing, impacts from climate change, and the severe limitation of small populations that will have a high likelihood of becoming extirpated due to random environmental and demographic events.

Protection, Status, and Ranks

Caribou in the former COSEWIC Southern Mountain population are currently listed as Threatened under the federal Species at Risk Act. This includes all caribou in the current Southern Mountain and Central Mountain DUs and 9 subpopulations in west-central and north-central BC in the Northern Mountain DU. Caribou in the former Northern Mountain population are listed as Special Concern under the federal Species at Risk Act. The majority of western mountain caribou habitat is on public land. Protected areas cover 22%, 41%, and 32% of the Northern Mountain, Central Mountain and Southern Mountain DU caribou ranges respectively, although most of the protected portion of the Central Mountain DU range covers high-elevation summer habitat. In addition to protected areas, in BC, Ungulate Winter Ranges and Wildlife Habitat Areas were established in 2009 to protect areas from forest harvesting or to guide forest harvesting activities.

Technical Summary - Northern Mountain population

Rangifer tarandus

Caribou – Northern Mountain population

Caribou – Population des montagnes du Nord (French name)

Range of occurrence in Canada:
British Columbia, Yukon, Northwest Territories

Demographic Information

Generation time
(calculated using IUCN formula)
9 year
Is there an [observed, inferred, or projected] continuing decline in number of mature individuals?
(Trend is known for 18 of 45 subpopulations representing approximately 54% of the current population; 9 are declining, mostly in the southern portion of the DU (including all 5 west-central BC subpopulations), and 2 are known to be increasing; 6 of 10 subpopulations with ≥3 years of late winter recruitment data have calf recruitment <15%)
Overall trend is unknown
Estimated percent of continuing decline in total number of mature individuals within [5 years or 2 generations]
(See above)
Overall trend is unknown
[Observed, estimated, inferred, or suspected] percent [reduction or increase] in total number of mature individuals over the last [10 years, or 3 generation].
(See above)
Overall trend is unknown
[Projected or suspected] percent [reduction or increase] in total number of mature individuals over the next [10 years, or 3 generations].
(See above. Subpopulations that are declining will likely continue to decline. However, fluctuations in the number of caribou in large subpopulations in the northern portion of the DU or refined population estimates for those subpopulations could mask declines of smaller subpopulations when considering the total number of caribou in the DU)
Overall trend is unknown
[Observed, estimated, inferred, or suspected] percent [reduction or increase] in total number of mature individuals over any [10 years, or 3 generations] period, over a time period including both the past and the future.
(See above)
Overall trend is unknown
Are the causes of the decline clearly reversible and understood and ceased?
(Causes of decline known for 9 declining subpopulations, but declines are not ceased and are not clearly reversible)
N/A Trend unknown for most of the 45 subpopulations
Are there extreme fluctuations in number of mature individuals?
No

Extent and Occupancy Information

Estimated extent of occurrence
1,050,174 km2
Index of area of occupancy (IAO)
523,672 km2
Is the population severely fragmented?
No
Number of locations Extent and Occupancy Information Footnote1
(Diverse threats across range)
N/A
Is there an inferred continuing decline in extent of occurrence?
No
Is there an [observed, inferred, or projected] continuing decline in index of area of occupancy?
(9 populations are known to be declining, leading to a reduction in density, but not total distribution)
Not likely
Is there an [observed, inferred, or projected] continuing decline in number of populations?
(some subpopulations have declined to low levels but no subpopulations have yet been extirpated in this DU; as more information is collected on distribution and movements of subpopulations, further refinement of subpopulation boundaries may result in a recalibration of the number of subpopulations)
No
Is there an [observed, inferred, or projected] continuing decline in number of locations Extent and Occupancy Information Footnote1?
N/A
Is there an observed continuing decline in and/or quality of habitat?
(in the southern portion of the DU and in more accessible ranges in the northern portion of the DU, industrial and other human activities resulting in habitat change favouring other prey species, and/or disturbance to caribou are continuing)
Yes
Are there extreme fluctuations in number of populations?
No
Are there extreme fluctuations in number of locations Extent and Occupancy Information Footnote1?
N/A
Are there extreme fluctuations in extent of occurrence?
No
Are there extreme fluctuations in index of area of occupancy?
No
Number of Mature Individuals (in each population)
Population No. of Mature Individuals
Hart River, YT 1853
Clear Creek,YT 801
Bonnet Plume, YT/NT 4200
Redstone, YT/NT 7300-10000
South Nahanni, YT/NT 1886
Coal River, YT/NT 413
La Biche, YT/NT 388
Chisana, YT 587
Kluane, YT 163
Aishihik, YT 1813
Klaza, YT 1065
Ethel Lake, YT 289
Moose Lake, YT 270
Tay River, YT 2907
Tatchun, YT 415
Pelly Herds, YT 876
Finlayson, YT 2657
Wolf Lake, YT 1240
Laberge, YT 176
Ibex, YT 748
Carcross, YT/BC 674
Atlin, YT/BC 514-857
Swan Lake, BC 515-686
Little Rancheria, YT/BC 672-1342
Horseranch, YT/BC 680-850
Level Kawdy, BC 1239
Edziza, BC 140
Tsenaglode, BC 85-340
Spatsizi, BC 2258
Liard Plateau, YT/BC 140
Rabbit, BC 1095
Muskwa, BC 828
Gataga, BC 220
Frog, BC 199
Finlay, BC 19
Pink Mountain, BC 1145
Graham, BC 637
Chase, BC 404
Wolverine, BC 298
Takla, BC 98
Telkwa, BC 19
Tweedsmuir, BC 248
Itcha-Ilgachuz, BC 1220
Rainbows, BC 43
Charlotte Alplands, BC 6
TOTAL 43,443 - 47,752

Quantitative Analysis

Probability of extinction in the wild is at least [20% within 20 years or 5 generations, or 10% within 100 years].
(Population viability analyses [PVAs] are available for only 2 subpopulations, both in west-central BC. The PVA for the Tweedsmuir subpopulation predicts that the population will decrease by at least 50% in 20 years and the model for the Itcha-Ilgachuz PVA also predicts a decline)
N/A

Threats (actual or imminent, to populations or habitats)

Altered predator-prey dynamics due to habitat change, human disturbance/habitat loss as a result of forest harvesting, mineral exploration and development and associated access, changes in habitat structure following Mountain Pine Beetle infestations and/or associated salvage logging, and motorized and non-motorized recreational activities.

Rescue Effect (immigration from outside Canada)

Status of outside population(s)?
Interior Alaska subpopulations have not been assessed with respect to COSEWIC designatable units
Ranked as secure in Alaska, but many subpopulations are declining
Is immigration known or possible?
Yes
Would immigrants be adapted to survive in Canada?
Yes
Is there sufficient habitat for immigrants in Canada?
Yes, in the northern part of the DU
Is rescue from outside populations likely?
(Possibly from Alaska but the subpopulations there have not been assessed with respect to COSEWIC designatable units)
Possibly from Alaska

Data-Sensitive Species

Is this a data-sensitive species?
No

Status History

COSEWIC:
The Northern Mountain population was designated Not at Risk in May 2000. This population was formerly designated as part of the “Western population”(now deactivated). Status re-examined and designated Special Concern in May 2002. Following the Designatable Unit report on Caribou (COSEWIC 2011), a new population structure was proposed and accepted by COSEWIC. This new Northern Mountain population is composed of all 36 subpopulations in the previous Northern Mountain population of Caribou in addition to 9 subpopulations from the previous (2002) Southern Mountain population. The Northern Mountain population was designated Special Concern in May 2014.

Status and Reasons for Designation

Status:
Special Concern
Alpha-numeric code:
Not applicable
Reason for Designation:
This population occurs in 45 subpopulations ranging from west-central British Columbia to Yukon and western Northwest Territories. Almost all of its distribution is in Canada, where it numbers about 43,000 - 48,000 mature individuals. There is little long-term (three generations) trend information, and many current estimates are based on survey data more than 5 years old. Currently 2 subpopulations are thought to be increasing, 7 are stable and 9 are declining. The condition of the remaining 27 subpopulations is unknown. The two largest subpopulations comprise > 15,000 animals, or 26-29% of the estimated population, and are thought to be stable. About half of the 45 subpopulations each contain < 500 individuals. All stable or increasing subpopulations are located in the northern part of the range, whereas 9 in the southern part of the range have declined by 27% since the last assessment. The status of northern subpopulations may be compromised in the future because of increasing threats, particularly land use change with industrial development causing shifts in predator-prey dynamics.
Criterion A (Decline in Total Number of Mature Individuals):
Unknown. Evidence for declines in some subpopulations, but overall trend unknown.
Criterion B (Small Distribution Range and Decline or Fluctuation):
Not applicable. EO and IAO exceed thresholds.
Criterion C (Small and Declining Number of Mature Individuals):
Not applicable. Population exceeds 10,000 mature individuals.
Criterion D (Very Small or Restricted Population):
Not applicable. Population exceeds 1,000 mature individuals, and IAO and number of locations exceeds thresholds.
Criterion E (Quantitative Analysis):
Not applicable.

Technical Summary - Central Mountain population

Rangifer tarandus

Caribou – Central Mountain population

Caribou – Population des montagnes du Centre (French name)

Range of occurrence in Canada:
British Columbia, Alberta

Demographic Information

Generation time
(calculated using IUCN formula)
9 yrs
Is there an [observed, inferred, or projected] continuing decline in number of mature individuals?
Yes
Estimated percent of continuing decline in total number of mature individuals within [5 years or 2 generations]
(based on the rate of decline for the past 2 generations). The decline rate is likely an underestimate, as the early surveys on which the decline was based for some subpopulations was more recent than 2 generations ago)
At least 62%
[Observed, estimated, inferred, or suspected] percent [reduction or increase] in total number of mature individuals over the last [10 years, or 3 generation].
(9 of 10 extant subpopulations are declining, one of which may be extirpated, and the trend for the other is unknown. Two additional subpopulations have been confirmed extirpated. The decline rate is likely an underestimate, as the early surveys on which the decline was based for some subpopulations was > 3 generations ago)
At least 64%
[Projected or suspected] percent [reduction or increase] in total number of mature individuals over the next [10 years, or 3 generations].
(based on the rate of decline for the past 3 generations)
At least 64%
[Observed, estimated, inferred, or suspected] percent [reduction or increase] in total number of mature individuals over any [10 years, or 3 generations] period, over a time period including both the past and the future.
(based on the rate of decline for the past 3 generations)
At least 64%
Are the causes of the decline clearly reversible and understood and ceased?
(Although the cause of the decline for most subpopulations has been attributed to altered predator-prey dynamics due to extensive habitat change from industrial activities, there may be additional contributing factors that are not well-understood; recovery of habitat will take decades and industrial activities are continuing and expanding. Subpopulations with lower levels of disturbance are also declining. Habitat destruction from industrial activities is ongoing and becoming more widespread).
Reversible: Unknown;Understood: Incomplete;Ceased: No
Are there extreme fluctuations in number of mature individuals?
Does not meet IUCN definition of extreme fluctuations
No

Extent and Occupancy Information

Estimated extent of occurrence
85,986 km2
Index of area of occupancy (IAO)
46,144 km2
Is the population severely fragmented?
Yes
Number of locations Extent and Occupancy Information Footnote2
N/A
Is there an inferred continuing decline in extent of occurrence?
(2 subpopulations have been extirpated since the previous status report in 2002 and the Bearhole/Redwillow portion of the Narraway subpopulation is considered to no longer occur in Alberta. EO cannot be directly compared with that of previous assessment due to change in DU boundaries)
Likely
Is there an [observed, inferred, or projected] continuing decline in index of area of occupancy?
(2 subpopulations have been extirpated since the previous status report in 2002. IAO cannot be directly compared with that of previous assessment due to change in DU boundaries)
Likely
Is there an [observed, inferred, or projected] continuing decline in number of populations?
(2 subpopulations have been extirpated since the previous status report in 2002)
Yes
Is there an [observed, inferred, or projected] continuing decline in number of locations Extent and Occupancy Information Footnote2?
N/A
Is there an observed continuing decline in and/or quality of habitat?
(industrial and other human activities resulting in habitat change favouring other prey species, and/or disturbance to caribou is continuing; a recent analysis of habitat change for east-central BC subpopulations reported loss of very high and high quality winter habitat from 0 to 66% [Williamson-Ehlers et al. 2013]).
Yes
Are there extreme fluctuations in number of populations?
No
Are there extreme fluctuations in number of locations Extent and Occupancy Information Footnote2?
N/A
Are there extreme fluctuations in extent of occurrence?
No
Are there extreme fluctuations in index of area of occupancy?
No
Number of Mature Individuals (in each population)
Population No. of Mature Individuals
Scott, BC 35
Moberly, BC 18
Kennedy Siding, BC 29
Quintette, BC 87
Narraway, BC/AB 78
Redrock-Prairie Creek, AB/BC 106
A La Peche, AB 75
Tonquin (Jasper), AB 30
Maligne (Jasper), AB 5
Brazeau (Jasper), AB 6
TOTAL 469

Quantitative Analysis

Probability of extinction in the wild is at least [20% within 20 years or 5 generations, or 10% within 100 years].
(PVAs were conducted on 10 subpopulations in three studies, but probability of extinction was not calculated for all)
None available.

Threats (actual or imminent, to populations or habitats)

Altered predator-prey dynamics due to habitat change resulting from forest harvesting and forest harvesting in combination with oil and gas exploration and development; human disturbance and other habitat loss due to multiple industrial activities including forest harvesting, coal exploration and development, and oil and gas exploration and development. Other factors include vehicle collisions, motorized recreation (ATV, snowmobiling), facilitated access for predators, small population effects, and infectious diseases that are likely to have increasing negative impacts in a changing climate.

Rescue Effect (immigration from outside Canada)

Status of outside population(s)?
Endemic to Canada
N/A
Is immigration known or possible?
No
Would immigrants be adapted to survive in Canada?
N/A
Is there sufficient habitat for immigrants in Canada?
N/A
Is rescue from outside populations likely?
No

Data-Sensitive Species

Is this a data-sensitive species?
No

Status History

COSEWIC:
Following the Designatable Unit report on caribou (COSEWIC 2011), a new population structure was proposed and accepted by COSEWIC. This resulted in the new Central Mountain population, composed of 12 subpopulations from the previous Southern Mountain population of Caribou (COSEWIC 2002). The Central Mountain population was designated Endangered in May 2014.

Status and Reasons for Designation

Status:
Endangered
Alpha-numeric code:
A2a+3a+4a; C1+C2a(i)
Reason for Designation:
This population is endemic to Canada and occurs in 10 extant subpopulations in east-central British Columbia and west-central Alberta in and around the Rocky Mountains. The current estimate for the population is 469 mature individuals and it has declined by at least 64% over the past 3 generations. One subpopulation in central British Columbia was confirmed extirpated in 2014, and an additional one in Banff in 2010. All extant subpopulations are estimated to contain fewer than 250 mature individuals, with 4 of these having fewer than 50. Two recognized subpopulations in 2002 have since split due to lack of dispersal within former ranges. All subpopulations have experienced declines of about 60% since the last assessment in 2002, and declines continue for all but one subpopulation, which has an unknown trend. Surveys have shown consistently high adult mortality and low calf recruitment, accelerating decline rates. Threats are continuing and escalating.
Criterion A (Decline in Total Number of Mature Individuals):
Meets EN A2a+3a+4a.
Meets Endangered A2a with overall decline (at least 64%) exceeding 50%. Causes have not ceased and may not be reversible. Trend calculated based on a) direct observation. Meets Endangered A3a due to inferred reduction of greater than 50% in the next 3 generations based on ongoing decline trends. Trend calculated based on a) direct observation. Meets Endangered A4a due to suspected inferred reduction of greater than 50% based on impact within a 3-generation period in the past or into the future. Trend calculated based on a) direct observation. A1 is not applicable because the causes of the decline have not ceased.
Criterion B (Small Distribution Range and Decline or Fluctuation):
Not applicable. EO and IAO both exceed thresholds.
Criterion C (Small and Declining Number of Mature Individuals):
Meets Endangered C1+2a(i). Meets Endangered C1 as population numbers fewer than 2,500 and is experiencing an estimated continuing 2-generation decline of greater than 62% (exceeds 20% threshold). Meets Endangered C2a(i) as there is a continuing decline in number of mature individuals and no subpopulation is estimated to contain more than 250 individuals.
Criterion D (Very Small or Restricted Population):
Meets Threatened D1 as population fewer than 1,000 mature individuals. D2 is not applicable as IAO and the number of locations exceed thresholds.
Criterion E (Quantitative Analysis):
Not applicable. Three PVAs were conducted on most subpopulations but probability of extinction was not predicted for all.

Technical Summary - Southern Mountain population

Rangifer tarandus

Caribou – Sourthern Mountain population

Caribou – Population des montagnes du Sud (French name)

Range of occurrence in Canada:
British Columbia

Demographic Information

Generation time
(calculated using IUCN formula)
9 yrs
Is there an [observed, inferred, or projected] continuing decline in number of mature individuals?
Yes
Estimated percent of continuing decline in total number of mature individuals within [5 years or 2 generations]
(based on the rate of decline for the past 2 generations. The decline rate may be underestimated as the early survey upon which the decline was based for some subpopulations was more recent than 2 generations ago)
At least 40%
[Observed, estimated, inferred, or suspected] percent [reduction or increase] in total number of mature individuals over the last [10 years, or 3 generation].
(14/15 subpopulations have declined over the last 3 generations, and 2 have been extirpated. Only 1 is known to be increasing and that subpopulation currently consists of only 78 mature individuals. The decline rate may be underestimated as the early survey upon which the decline was based for some subpopulations was more recent than 3 generations ago)
At least 45%
[Projected or suspected] percent [reduction or increase] in total number of mature individuals over the next [10 years, or 3 generations].
(based on the rate of decline for the past 3 generations)
At least 45%
[Observed, estimated, inferred, or suspected] percent [reduction or increase] in total number of mature individuals over any [10 years, or 3 generations] period, over a time period including both the past and the future.
(based on the rate of decline for the past 3 generations)
At least 45%
Are the causes of the decline clearly reversible and understood and ceased?
(Although the cause of the decline has been attributed to altered predator-prey dynamics due to habitat change resulting from forest harvesting in adjacent valley bottoms, there may be additional contributing factors that are not well-understood; recovery of habitat will take decades and industrial activities are continuing and expanding)
Reversible: Unknown Understood: Incomplete Ceased: No
Are there extreme fluctuations in number of mature individuals?
No

Extent and Occupancy Information

Estimated extent of occurrence
118,2401 km2
Index of area of occupancy (IAO)
46,324 km2
Is the population severely fragmented?
No
Number of locations Extent and Occupancy Information Footnote3
(diverse threats across range)
N/A
Is there an inferred continuing decline in extent of occurrence?
(2 subpopulations have been extirpated since the previous status report in 2002; EO cannot be directly compared with that of previous assessment due to change in DU boundaries)
Yes
Is there an [observed, inferred, or projected] continuing decline in index of area of occupancy?
(2 subpopulations have been extirpated since the previous status report in 2002. IAO cannot be directly compared with that of previous assessment due to change in DU boundaries)
Yes
Is there an [observed, inferred, or projected] continuing decline in number of populations?
(2 subpopulations have been extirpated since the previous status report in 2002)
Yes
Is there an [observed, inferred, or projected] continuing decline in number of locations Extent and Occupancy Information Footnote3?
N/A
Is there an observed continuing decline in and/or quality of habitat?
Yes
Are there extreme fluctuations in number of populations?
No
Are there extreme fluctuations in number of locations Extent and Occupancy Information Footnote3?
N/A
Are there extreme fluctuations in extent of occurrence?
No
Are there extreme fluctuations in index of area of occupancy?
No
Number of Mature Individuals (in each population)
Population No. of Mature Individuals
South Selkirks 20
Purcells South 22
Nakusp 54
Duncan 2
Central Rockies 4
Monashee 4
Frisby Boulder 12
Columbia South 6
Columbia North 157
Groundhog 11
Wells Gray 341
Barkerville 78
North Cariboo Mountains 202
Narrow Lake 45
Hart Ranges 398
TOTAL 1,356

Quantitative Analysis

Probability of extinction in the wild is at least [20% within 20 years or 5 generations, or 10% within 100 years].
(2 PVAs have been conducted on subpopulations within the Southern Mountain DU: one was based on vital rates [Wittmer et al. 2010], and one on population estimates from surveys [Hatter 2006]. Wittmer et al. [2010] found that 8/10 had probabilities >20% within 45 yrs (5 generations) and Hatter [2006] predicted quasi-extinction [<20 animals] in 20 years was >20% for 13 of 15 subpopulations)
Yes

Threats (actual or imminent, to populations or habitats)

Altered predator/prey dynamics due to habitat change resulting from forest harvesting in adjacent low elevation valley bottoms, and from increased predator efficiency using trails created by snowmobiling and heli-skiing. Infectious diseases are likely to cause increasing negative impacts, particularly in a changing climate.

Rescue Effect (immigration from outside Canada)

Status of outside population(s)?
Endangered in Idaho and Washington
Is immigration known or possible?
No
Would immigrants be adapted to survive in Canada?
Possibly
Is there sufficient habitat for immigrants in Canada?
N/A
Is rescue from outside populations likely?
No

Data-Sensitive Species

Is this a data-sensitive species?
No

Status History

COSEWIC:
The Southern Mountain population was designated Threatened in May 2000. This population was formerly designated as part of the “Western population” (now deactivated). Status re-examined and confirmed in May 2002. Following the Designatable Unit report on Caribou (COSEWIC 2011), a new population structure was proposed and accepted by COSEWIC. This resulted in the new Southern Mountain population, composed of 17 subpopulations from the former Southern Mountain population (COSEWIC 2002). The remaining subpopulations were assigned to the new Central and Northern Mountain populations.The Southern Mountain population was designated Endangered in May 2014.

Status and Reasons for Designation

Status:
Endangered
Alpha-numeric code:
A3a+4a; C1
Reason for Designation:
This population is largely restricted to Canada, except for < 40 animals in Idaho and Washington. It occurs in 15 extant subpopulations in southeastern British Columbia. Two subpopulations have been extirpated since 2002. The current estimate for the population is 1,356 mature individuals, which has declined by at least 45% in the past three generations, and 27% since the last assessment in 2002. All but two extant subpopulations are estimated to contain fewer than 250 mature individuals, with 9 of these having fewer than 50, and 6 with fewer than 15 mature individuals. Dispersal within the ranges of 11 subpopulations is severely limited. Surveys have shown consistently high adult mortality and low calf recruitment, accelerating decline rates. Threats are continuing and escalating.
Criterion A (Decline in Total Number of Mature Individuals):
Meets Endangered A3a based on inferred reduction of >50% in the next 3 generations based on ongoing decline trends. Trend calculated based on a) direct observation.
Meets Endangered A4a based on suspected inferred reduction of >50% based on impact within a 3-generation period in the past or into the future. Trend calculated based on a) direct observation.
Meets Threatened A2a with overall decline (at least 45%) exceeding 30%. Causes have not ceased and may not be reversible. Trend calculated based on a) direct observation.
A1 is not applicable as causes of decline have not ceased.
Criterion B (Small Distribution Range and Decline or Fluctuation):
Not applicable. EO and IAO both exceed thresholds.
Criterion C (Small and Declining Number of Mature Individuals):
Meets Endangered C1 as population contains < 2,500 mature individuals and shows a 2-generation decline of >40% (exceeds 20% threshold).
Meets Threatened C2a(i). There is a continuing decline and all subpopulations estimated to contain < 1000 mature individuals (all but two < 250, almost meeting Endangered).
Criterion D (Very Small or Restricted Population):
D1 is not applicable. Population > 1,000 individuals.
D2 is not applicable. IAO and # locations exceed thresholds.
Criterion E (Quantitative Analysis):
Meets Endangered E. Two PVAs conducted on 10/15 and 15/15 extant subpopulations respectively, predicted extinction risk > 20% in approximately 45 years (5 generations) for 13.

Preface

This report is based on information collected since the 2002 COSEWIC assessment and status report on the Woodland Caribou Rangifer tarandus caribou in Canada (COSEWIC 2002), and the report on Designatable Units for Caribou in Canada (COSEWIC 2011). Western mountain caribou (and the subject of this report) were first assessed as part of the “Western Population” in 1984 (Kelsall 1984). This unit was then split into the “Northern Mountain” and “Southern Mountain” populations in 2000, and assessed as Not at Risk and Threatened, respectively, but with no accompanying status report. The statuses of both populations were re-examined in May 2002 as two of four “ecotypes” of the Woodland Caribou subspecies (Rangifer tarandus caribou) considered in a larger report (COSEWIC 2002) that also included the “distinct population” of Newfoundland caribou. These mountain caribou ecotypes (Northern Mountain and Southern Mountain) were based on COSEWIC’s National Ecological Areas of the same name. At that time, the Southern Mountain population was reaffirmed as Threatened, and Northern Mountain population was assessed as Special Concern.

This assessment follows an analysis of designatable unit structure of caribou in Canada undertaken by COSEWIC as a special project (COSEWIC 2011) to define the DUs for future status assessments and reassessments of this species according to the latest guidelines. Although prevailing taxonomy (Banfield 1961) recognizes four native extant and one extinct subspecies in North America (including Woodland Caribou, Rangifer tarandus caribou), it is outdated and does not capture the variability of caribou across their range in Canada. Based on the COSEWIC DU criteria for discreteness and significance (COSEWIC 2013), western mountain caribou were separated into three DUs: Northern Mountain caribou of BC, Yukon and NT (DU7), Central Mountain caribou of central BC and Alberta (DU8), and Southern Mountain caribou of southern BC (DU9) (COSEWIC 2011).

Much new research has been conducted on western mountain caribou since the last report, including new population survey information. Two subpopulations in the Southern Mountain DU and 2 in the Central Mountain DU have been confirmed as extirpated since the last assessment. This report also includes updates from traditional ecological knowledge collected and summarized from First Nations and Métis sources by the COSEWIC Aboriginal Traditional Knowledge (ATK) Subcommittee. These sources have been compiled and assessed in two reports: the Caribou ATK Source Report and the Caribou ATK Assessment Report.

COSEWIC logo

COSEWIC History

The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) was created in 1977 as a result of a recommendation at the Federal-Provincial Wildlife Conference held in 1976. It arose from the need for a single, official, scientifically sound, national listing of wildlife species at risk. In 1978, COSEWIC designated its first species and produced its first list of Canadian species at risk. Species designated at meetings of the full committee are added to the list. On June 5, 2003, the Species at Risk Act (SARA) was proclaimed. SARA establishes COSEWIC as an advisory body ensuring that species will continue to be assessed under a rigorous and independent scientific process.

COSEWIC Mandate

The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) assesses the national status of wild species, subspecies, varieties, or other designatable units that are considered to be at risk in Canada. Designations are made on native species for the following taxonomic groups: mammals, birds, reptiles, amphibians, fishes, arthropods, molluscs, vascular plants, mosses, and lichens.

COSEWIC Membership

COSEWIC comprises members from each provincial and territorial government wildlife agency, four federal entities (Canadian Wildlife Service, Parks Canada Agency, Department of Fisheries and Oceans, and the Federal Biodiversity Information Partnership, chaired by the Canadian Museum of Nature), three non-government science members and the co-chairs of the species specialist subcommittees and the Aboriginal Traditional Knowledge subcommittee. The Committee meets to consider status reports on candidate species.

Definitions (2014)

Wildlife Species

A species, subspecies, variety, or geographically or genetically distinct population of animal, plant or other organism, other than a bacterium or virus, that is wild by nature and is either native to Canada or has extended its range into Canada without human intervention and has been present in Canada for at least 50 years.

Extinct (X)
A wildlife species that no longer exists.
Extirpated (XT)
A wildlife species no longer existing in the wild in Canada, but occurring elsewhere.
Endangered (E)
A wildlife species facing imminent extirpation or extinction.
Threatened (T)
A wildlife species likely to become endangered if limiting factors are not reversed.
Special Concern (SC)Footnotea
A wildlife species that may become a threatened or an endangered species because of a combination of biological characteristics and identified threats.
Not at Risk (NAR)Footnoteb
A wildlife species that has been evaluated and found to be not at risk of extinction given the current circumstances.
Data Deficient (DD)Footnotec
A category that applies when the available information is insufficient (a) to resolve a species’ eligibility for assessment or (b) to permit an assessment of the species’ risk of extinction.

The Canadian Wildlife Service, Environment Canada, provides full administrative and financial support to the COSEWIC Secretariat.

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