Fringed bat COSEWIC assessment and status report: chapter 12
Technical Summary
Myotis thysanodes
Fringed Bat – Chauve-souris à queue frangée
Range of Occurrence in Canada:
British Columbia
Extent and Area information
extent of occurrence (EO) (km²) :
8,650 km²
specify trend (decline, stable, increasing, unknown) :
Unknown
are there extreme fluctuations in EO (> 1 order of magnitude)?
Unknown
area of occupancy (AO) (km²) :
Unknown
specify trend (decline, stable, increasing, unknown)
-
are there extreme fluctuations in AO (> 1 order magnitude)?
-
number of extant locations :
33*
specify trend in # locations (decline, stable, increasing, unknown) :
Unknown
are there extreme fluctuations in # locations (>1 order of magnitude)?
Unknown
habitat trend: specify declining, stable, increasing or unknown trend in area, extent or quality of habitat :
Unknown
Population information
generation time (average age of parents in the population) (indicate years, months, days, etc.) :
2
number of mature individuals (capable of reproduction) in the Canadian population (or, specify a range of plausible values) :
Unknown
total population trend: specify declining, stable, increasing or unknown trend in number of mature individuals :
Unknown
if decline, % decline over the last/next 10 years or 3 generations, whichever is greater (or specify if for shorter time period)
-
are there extreme fluctuations in number of mature individuals (> 1 order of magnitude)?
-
is the total population severely fragmented (most individuals found within small and relatively isolated (geographically or otherwise) populations between which there is little exchange, i.e., < 1 successful migrant / year)?
No
list each population and the number of mature individuals in each
-
specify trend in number of populations (decline, stable, increasing, unknown)
-
are there extreme fluctuations in number of populations (>1 order of magnitude)?
-
Threats
- disturbance of maternity colonies and night roosts
- loss of riparian habitat
- impacts of pesticides on invertebrate prey
Rescue Effect (immigration from an outside source)
Moderate
does species exist elsewhere (in Canada or outside)? Yes
status of the outside population(s)?
- Uncommon
- Idaho S1?
- Montana S3
- Washington S3?
is immigration known or possible?
Yes
would immigrants be adapted to survive here?
Yes
is there sufficient habitat for immigrants here?
Yes
Quantitative Analysis
* 33 occurrences; 18 element occurrences. An element occurrence for small bats is defined by the Heritage Ranking System as sites occupied historically or at present that are separated by 10 km or more.
Other Status
COSEWIC: Special Concern 1988
British Columbia: S2S3
Status and Reasons for Designation
Status: Data Deficient
Reasons for Designation: This species is rarely reported in its Canadian range. There are, however, a few sites in the Okanagan Valley where they regularly can be captured during the summer. There is a lack of data about the extent of its Canadian range and the habitat that is important for foraging and roosting. We also do not know the population size or trends, nor any key demographic characteristics, such as population structure, reproduction or survival rates. It is not known if this species overwinters in Canada or migrates south for the winter; however, there are maternity colonies recorded in Canada.
Applicability of Criteria
- Criterion A (Declining Total Population): Population sizes unknown.
- Criterion B (Small Distribution, and Decline or Fluctuation): Extent of distribution unknown.
- Criterion C (Small Total Population Size and Decline): No evidence of population decline.
- Criterion D (Very Small Population or Restricted Distribution): Unknown.
- Criterion E (Quantitative Analysis): Probability of extinction in Canada, unknown.
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