Rusty cord-moss (Entosthodon rubiginosus) COSEWIC assessment and status report: chapter 12

Technical Summary

Entosthodon rubiginosus

Rusty cord moss – Entosthodon rouilleux

Range of Occurrence in Canada:

British Columbia

Extent and Area Information

Extent of occurrence (EO)(km²) :

20,000 km² (excluding the unconfirmed site)

Specify trend in EO :

unknown

Are there extreme fluctuations in EO?

no

Area of occupancy (AO) (km²) :

±0.01 km² based on actual size of habitat

Specify trend in AO :

unknown

Are there extreme fluctuations in AO?

unknown

Number of known or inferred current locations :

3 (White Lake, SE of Princeton, south of Riske Creek)

Specify trend in # :

Stable? (The Kamloops population was not relocated)

Are there extreme fluctuations in number of locations?

No

Specify trend in area, extent or quality of habitat :

  • White Lake is stable.
  • Princeton is heavily disturbed in places and a portion of the population has been lost.
  • Riske Creek appears stable.

Population Information

Generation time (average age of parents in the population) :

unknown, but species is possibly perennial

Number of mature individuals :

The species may be difficult to detect, therefore population sizes may be underestimated.

  • <24 total
  • <20 at White Lake
  • 1 at Riske Creek
  • 3 at Princeton

Total population trend:

Unknown

% decline over the last/next 10 years or 3 generations.

Unknown

Are there extreme fluctuations in number of mature individuals?

Unknown

Is the total population severely fragmented?

Yes

Specify trend in number of populations:

Unknown

Are there extreme fluctuations in number of populations?

Unknown

List populations with number of mature individuals in each :

see number of mature individuals, above

Threats (actual or imminent threats to populations or habitats)

  • Impacts of cattle; it is not known what level of disturbance the species can withstand and continue to persist at a site.
  • Development, road building, off road vehicles.

Rescue Effect (immigration from an outside source)

Status of outside population(s)? 

Type locality in Montana has not been relocated.

Is immigration known or possible?

not likely

Would immigrants be adapted to survive in Canada?

Yes

Is there sufficient habitat for immigrants in Canada?

Yes

Is rescue from outside populations likely?

No

Quantitative Analysis

Not applicable

Previous Status

  • COSEWIC: none
  • NatureServe: critically imperiled – highly vulnerable globally
  • Montana: SH

Status and Reasons for Designation

Status:  Endangered

Alpha-numeric code:  B2ab(iii); C2a(i); D1

Reasons for Designation: This species is endemic to western North America where it occurs in southern British Columbia, and has been reported from Montana, Arizona, and New Mexico. This moss has a highly restricted distribution in south-central British Columbia where only four populations have been found. Of these, three populations are extant, and one was not relocated; the species is not abundant at any known site. The species' habitat is a narrow band of shoreline dominated by grasses and other mosses in seasonally wet, alkaline habitats. Two populations have been affected by trampling by horses or cattle, and all sites examined have been impacted to varying degrees by domestic animals. At least a portion of one population has been lost as result of trampling by domestic animals.

Applicability of Criteria

Criterion A (Declining Total Population): Not applicable, does not meet criteria for decline.

Criterion B (Small Distribution, and Decline or Fluctuation): Meets thresholds for Endangered, 2 (area of occupancy less than 100 m²) a (severely fragmented) b, iii (decline in quality of habitat in two populations).

Criterion C (Small Total Population Size and Decline): Meets thresholds for Endangered, 2a(i) (number of individuals < 2500 and no population estimated to contain > 250 individuals).

Criterion D (Very Small Population or Restricted Distribution): Meets threshold for Endangered, D1 (number of individuals < 250).

Criterion E (Quantitative Analysis): Not available.

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