Allegheny Mountain dusky salamander COSEWIC assessment and status report: chapter 13
Technical Summary
Range of Occurrence in Canada: Quebec
Extent and Area Information
Extent of occurrence (EO)(km2)
EO measured by drawing a polygon around all known sites of occurrence. Determined by Joel Bonin.
< 50 km2
Specify trend in EO
unknown
Are there extreme fluctuations in EO?
unknown
Area of occupancy (AO)(km2)
The area of occupancy is an estimate that includes all streams, seeps and adjacent terrestrial sites within the EO where salamanders have been found.
< 10 km2
Specify trend in AO
unknown
Are there extreme fluctuations in AO?
unknown
Number of known or inferred current locations
one
Specify trend in # locations
none
Are there extreme fluctuations in number of locations?
no
Specify trend in area, extent or quality of habitat
none
Population Information
Generation time (average age of parents in the population)
Sexual maturity occurs 2-3 years for males and 3-4 years for females
Approximately 4 yrs.
Number of mature individuals
based on abundance surveys so far taken
Unknown, probably <1000
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 but possible
Is the total population severely fragmented?
Yes
Specify trend in number of populations
none
Are there extreme fluctuations in number of populations?
No
List populations with number of mature individuals in each:
Covey Hill (Qc): probably <1000
Threats (actual or imminent threats to populations or habitats)
- Changes to the quality or abundance of ground or surface water.
- Deforestation for agricultural or urban development that damages or destroys terrestrial forest habitat, increasing siltation and altering hydrological regimes
- contamination of ground or surface water
- stochastic environmental events due to the small sizes of the populations
- physical barriers such as roads and cultivated fields compromise the species' movements
- all terrain vehicle use
Rescue Effect (immigration from an outside source)
Status of outside population(s)?
USA: Desmognathus ochrophaeus in the United States has a large and continuous range and is considered common with no major threats. It is ranked as N5 in the U.S., indicating that the species is secure nationally. It is secure in 7 states including New York State.
Is immigration known or possible?
The Covey Hill population is >90km from the nearest US population.
No
Would immigrants be adapted to survive in Canada?
Populations in the U.S. are located in similar habitats and climates as those in Canada.
Yes, quite likely
Is there sufficient habitat for immigrants in Canada?
The Canadian range is very restricted and suitable habitats are already occupied by this species.
No
Is rescue from outside populations likely?
No
Quantitative Analysis
NA
Current Status
COSEWIC: Threatened (2001, 2007)
Status and Reasons for Designation
Status: Threatened
Alpha-numeric code: D2
Reasons for Designation: This is a small and secretive salamander, with aquatic larvae, that inhabits forested brooks, cascades, springs, or seeps where there is abundant cover in the form of crevices between stones, leaf litter, or logs. This species has a very small range of less than 100 km2 in the Great Lakes/St. Lawrence faunal province in a single locality at the northernmost edge of the Adirondack Mountains. At this locality, the salamanders occupy some 8 to 10 streams and seeps with a total area of occupancy of under 10 km2. All of these streams emanate from a single water source. The locality is isolated from any other population of the same species; the nearest other locality is about 90 km away in New York State. Its minute range makes this salamander highly susceptible to stochastic events and the species would easily become endangered if major changes to its habitat were to take place. The major threats to this salamander in Great Lakes/St. Lawrence faunal province are any that could affect the water table and dry out seeps and springs in its habitat, degrade groundwater flow and quality or deplete groundwater reserves. Logging at the single water source could destroy terrestrial habitat by increasing siltation in streams and altering hydrological regimes.
Applicability of Criteria
Criterion A (Declining Total Population):
Insufficient information.
Criterion B (Small Distribution, and Decline or Fluctuation):
The distribution in Canada is very small but there is insufficient information available to assess decline.
Criterion C (Small Total Population Size and Decline):
The number of individuals in Canada is likely under 1000 adults but there is insufficient information available to assess decline.
Criterion D (Very Small Population or Restricted Distribution):
The species has a very restricted range. The sole location is highly susceptible to any changes in water quality or quantity. The species thus is capable of becoming highly endangered very rapidly.
Criterion E (Quantitative Analysis):
Not applicable.
Range of Occurrence in Canada: Ontario
Extent and Area Information
Extent of occurrence (EO)(km2)
EO Determined by OMNR.
0.0053 km2
Specify trend in EO
unknown
Are there extreme fluctuations in EO?
unknown
Area of occupancy (AO)(km2)
The area of occupancy is an estimate that includes all stream/seep and adjacent terrestrial sites within the EO where salamanders were found.
0.0053 km2
Specify trend in AO
unknown
Are there extreme fluctuations in AO?
unknown
Number of known or inferred current locations
one
Specify trend in # locations
none
Are there extreme fluctuations in number of locations?
no
Specify trend in area, extent or quality of habitat
none
Population Information
Generation time (average age of parents in the population)
Sexual maturity occurs 2-3 years for males and 3-4 years for females
Approximately 4 yrs.
Number of mature individuals
based on abundance surveys so far taken. A total of 22 individuals have been identifed
<100
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 but possible
Is the total population severely fragmented?
Yes
Specify trend in number of populations
none
Are there extreme fluctuations in number of populations?
No
List populations with number of mature individuals in each:
Niagara Gorge (Ont): <100
Threats (actual or imminent threats to populations or habitats)
- Changes to the quality or abundance of ground or surface water.
- Deforestation for agricultural or urban development that damages or destroys terrestrial forest habitat, increasing siltation and altering hydrological regimes
- contamination of ground or surface water
- stochastic environmental events due to the small sizes of the populations
- collecting
- human recreation in or near salamander habitat
Rescue Effect (immigration from an outside source)
Status of outside population(s)?
USA: Desmognathus ochrophaeus in the United States has a large and continuous range and is considered common with no major threats. It is ranked as N5 in the U.S., indicating that the species is secure nationally. It is secure in 7 states including New York State.
Is immigration known or possible?
The population is isolated by the large and fast flowing Niagara River and is 22 km from the closest US population.
No
Would immigrants be adapted to survive in Canada?
Populations in the U.S. are located in similar habitats and climates as those in Canada.
Yes, quite likely
Is there sufficient habitat for immigrants in Canada?
The Canadian range is very restricted and suitable habitats are already occupied by this species.
No
Is rescue from outside populations likely?
No
Quantitative Analysis
NA
Current Status
COSEWIC: Endangered (2007)
Status and Reasons for Designation
Status: Endangered
Alpha-numeric code: D1
Reasons for Designation: This is a small and secretive salamander, with aquatic larvae, that inhabits forested brooks, cascades, springs, or seeps where there is abundant cover in the form of crevices between stones, leaf litter, or logs. This species’ entire range in the Carolinian faunal province consists of a single, cascading stream in the Niagara Gorge, occupying no more than about 0.005 km2. The locality is isolated from any other population of the same species, the nearest being about 22 km away in New York State. Surveys to date have located and identified some 22 individuals and indicate a total adult population that is probably fewer than 100 individuals. Its minute range makes this salamander highly susceptible to stochastic events and the species would easily and rapidly become extirpated if any change to its habitat were to take place. The major threats to this salamander in Carolinian faunal province are any activities that could affect the water table and dry out the spring that supplies its habitat, degrade groundwater flow and quality or deplete groundwater reserves.
Applicability of Criteria
Criterion A (Declining Total Population):
Insufficient information.
Criterion B (Small Distribution, and Decline or Fluctuation):
The distribution in Canada is miniscule but there is insufficient information available to assess decline.
Criterion C (Small Total Population Size and Decline):
The number of individuals in Canada is likely under 100 adults but there is insufficient information available to assess decline.
Criterion D (Very Small Population or Restricted Distribution):
The species has population size of probably less than 100 individuals in a very restricted single location that is highly susceptible to any changes in water quality or quantity. The species thus is capable of being extirpated very rapidly.
Criterion E (Quantitative Analysis):
Not applicable.
Page details
- Date modified: