Swift fox (Vulpes velox) COSEWIC assessment and status report 2009: chapter 11
Technical Summary
Vulpes velox
Swift Fox – Renard véloce
Demographic Information
continuing decline in number of mature individuals?
number of mature individuals within [5 years
or 2 generations]
percent [reduction or increase] in total number
of mature individuals over the last [10 years,
or 3 generations].
or increase] in total number of mature individuals
over the next [10 years, or 3 generations].
[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.
understood and ceased?
individuals?
Extent and Occupancy Information
Moehrenschlager and Moehrenschlager (2006) used townships rather than 2x2 grid to calculate AO.
For Swift Fox in Canada, disease is a “single threatening event” that can rapidly affect all individuals of the taxon present. This threat is real for Swift fox because: 1) high recorded seroprevalence of several viruses in the current population, 2) documented evidence of unpredictable disease outbreaks driving the near extirpation of many endangered canid populations worldwide, and 3) Swift Fox in Canada exist as one meta–population with evidence of long–range dispersal between sub–populations, and therefore one epidemiological unit. This meets the IUCN definition of 1 location.
continuing decline in extent of occurrence?
continuing decline in index of area of occupancy?
continuing decline in number of populations?
continuing decline in number of locations?
continuing decline in [area, extent and/or quality]
of habitat?
populations?
locations*?
occurrence?
* See definition of location.
Number of Mature Individuals (in each population)
Quantitative Analysis
Threats (actual or imminent, to populations or habitats)
- Predation (Coyotes)
- Habitat alteration (conversion to agriculture, energy development, roads, climate change)
- Disease
- Poisoning
- Trapping
- Road mortality
- Interspecific competition (Coyotes, Red Foxes)
Rescue Effect (immigration from an outside source)
Rescue is likely from Montana only, but not from core Swift Fox range in the U.S.
Current Status
Status and Reasons for Designation
Reasons for Designation:
This species was extirpated from Canada in the 1930s. Following reintroduction programs in Alberta and Saskatchewan initiated in 1983, they have re–established populations in these areas and in northern Montana. Population numbers and distribution have increased since that time, with the current estimate in Canada having doubled to 647 since the last COSEWICassessment in 2000. Connectivity between populations has also improved during this time, particularly through northern Montana. Since 2001, population numbers and distribution have remained stable and habitat for this species within Canada appears to be saturated. Most improvement in overall population status can be attributed to populations in Montana, which are still demonstrating increasing trends in numbers and distribution. Deteriorating habitat in Canada and the threat of disease (as seen in other canids) could threaten the continued recovery of this species.
Applicability of Criteria
Criterion A (Decline in Total Number of Mature Individuals):
Not applicable. The current Canadian population(s) increased after reintroductions. There is no indication that the total number of mature individuals has declined over the last 10 years/3 generations, or might do so in the next 10 years/3 generations.
Criterion B (Small Distribution Range and Decline or Fluctuation):
Not applicable. While the extent of occurrence hovers at about the threshold for Threatened under criterion B1 (21 544 km²), there is no clear fit for the accompanying conditions that must be met. Swift Fox population(s) in Canada do not undergo extreme fluctuations and although there is continued habitat decline in the region, the extent to which this is having or will have an impact on current Swift Fox range and population status is unknown.
Criterion C (Small and Declining Number of Mature Individuals):
Not applicable. There is no indication of a declining number of mature individuals
Criterion D (Very Small Population or Restricted Distribution):
Meets Threatened D1+2. D1: current population estimate for mature individuals for Swift Fox is 647, which places it well above 250 (Endangered) but below the 1000 threshold for Threatened. D2: Swift Fox in Canada are in one connected location, and subject to the possibility of one threatening event, disease, affecting all members of the species. They therefore qualify as Threatened under this criterion.
Criterion E (Quantitative Analysis):
Not applicable. There is no population projection suggesting that the probability of extinction of the species in the wild is > 10% (100 yrs) or > 20% (20 years/5 generations).
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