BC Conservation Data Centre: Species Summary
Mustela richardsonii
Ermine
| Scientific Name: | Mustela richardsonii Bonaparte, 1838 | ||||||||||
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| Scientific Name Synonyms: |
Mustela erminea
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| English Name: | Ermine | ||||||||||
| Classification / Taxonomy | |||||||||||
| Scientific Name - Concept Reference: | Colella, J.P., L.M. Frederick, S.L. Talbot and J.A. Cook. 2021. Extrinsically reinforced hybrid speciation within Holarctic ermine (Mustela spp.) produces an insular endemic. Diversity and Distributions 27: 747-762. | ||||||||||
| Classification Level: | Species | ||||||||||
| Taxonomy Comments: | Based on Colella et al. 2021, Mustela erminea haidarum = Mustela haidarum, Mustela erminea = Mustela richardsonii | ||||||||||
| Species Group: | Vertebrate Animal | ||||||||||
| Species Code: | M-MUER | ||||||||||
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| Conservation Status / Legal Designation | |||||||||||
| Global Status: | G5 (Apr 2016) | ||||||||||
| Provincial Status: | S5 (Mar 2024) | ||||||||||
| BC List: | Yellow | ||||||||||
| Provincial FRPA list: | |||||||||||
| Provincial Wildlife Act: | |||||||||||
| COSEWIC Status: | |||||||||||
| SARA Schedule: | |||||||||||
| General Status Canada: | 4 - Secure (2005) | ||||||||||
| Ecology & Life History | |||||||||||
| General Description: | |||||||||||
| Global Reproduction Comments: | Breeds July-August. Gestation lasts 255 days. Litter of 4-9 (average 6-7) is born mid-April to early May. Females are sexually mature in 3-4 months, males in 12 months (probably). Delayed implantation. | ||||||||||
| Global Ecology Comments: | Home range averages 12-16 ha (Jackson 1961). In southern Ontario, density over 95 ha averaged 6 per sq km; home range averaged 20-25 ha for males, smaller for females; most individuals remained on study site less than 1 year (Simms 1979). | ||||||||||
| Migration Characteristics: (Global / Provincial) | |||||||||||
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Nonmigrant: Local Migrant: Distant Migrant: Within Borders Migrant: |
Y / N / N / na / |
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| Habitats: (Type / Subtype / Dependence) |
Agriculture / Cultivated Field / Facultative - frequent use
Agriculture / Hedgerow / Facultative - frequent use Agriculture / Pasture/Old Field / Facultative - frequent use Alpine/Tundra / Krummholtz / Facultative - occasional use Alpine/Tundra / Tundra / Facultative - frequent use Forest / Conifer Forest - Dry / Facultative - frequent use Forest / Conifer Forest - Mesic (average) / Facultative - frequent use Forest / Conifer Forest - Moist/wet / Facultative - occasional use Forest / Deciduous/Broadleaf Forest / Facultative - occasional use Grassland/Shrub / Shrub - Natural / Facultative - frequent use Other Unique Habitats / Avalanche Track / Facultative - occasional use Riparian / Gravel Bar / Facultative - frequent use Riparian / Riparian Forest / Facultative - frequent use Riparian / Riparian Herbaceous / Facultative - frequent use Riparian / Riparian Shrub / Facultative - frequent use Rock/Sparsely Vegetated Rock / Talus / Facultative - occasional use |
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| Global Habitat Comments: | Prefers wooded areas with thick understory near watercourses. Rarely occurs in heavily forested regions. Has adapted to a wide variety of habitats. Dens in hollow log or under log, stump, roots, brushpile, or rocks. In winter in southern Ontario, usually stayed beneath snow surface (Simms 1979). | ||||||||||
| Food Habits: |
Carnivore: Adult, Immature
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| Global Food Habits Comments: | Mainly small mammals, and occasionally other small vertebrates and insects. | ||||||||||
| Global Phenology: |
Crepuscular: Adult, Immature
Nocturnal: Adult, Immature |
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| Global Phenology Comments: | Mainly nocturnal, can been seen frequently during the day. | ||||||||||
| Provincial Phenology: (1st half of month/ 2nd half of month) |
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| Colonial Breeder: | N | ||||||||||
| Length(cm)/width(cm)/Weight(g): | 34/ / 182 | ||||||||||
| Elevation (m) (min / max): |
Global:
Provincial: |
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| Distribution | |||||||||||
| Endemic: | N | ||||||||||
| Global Range Comment: | This species is a widespread continental North American species, ranging across Canada south through most of the northern United States to central California, northern Arizona (Berna 1991), northern New Mexico, Iowa, the Great Lakes region, Pennsylvania, and northern Virginia (Fagerstone 1987) (Colella et al. 2021). The species in most of Alaska now refers to the Beringian species, Mustela erminea. | ||||||||||
| Authors / Contributors | |||||||||||
| Global Information Author: | Hammerson, G. | ||||||||||
| Last Updated: | Apr 19, 1994 | ||||||||||
| Provincial Information Author: | |||||||||||
| Last Updated: | |||||||||||
| References and Related Literature | |||||||||||
Hatler, D.F., Nagorsen, D.W. and Beal, A.M., 2008. Carnivores of British Columbia (Vol. 5). Victoria, British Columbia, Canada: Royal BC Museum. |
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Wilson, D. E., and D. M. Reeder (editors). 1993. Mammal species of the world: a taxonomic and geographic reference. Second edition. Smithsonian Institution Press, Washington, DC. xviii + 1206 pp. Available online at: http://www.nmnh.si.edu/msw/. |
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Please visit the website Conservation Status Ranks for definitions of the data fields used in this summary report.
Suggested Citation:
B.C. Conservation Data Centre. 1994. Species Summary: Mustela richardsonii. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Apr 4, 2026).