BC Conservation Data Centre: Conservation Status Report
Sorex tundrensis
Tundra Shrew
| Scientific Name: | Sorex tundrensis |
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| English Name: | Tundra Shrew |
| Provincial Status Summary | |
| Status: | S1S2 |
| Date Status Assigned: | March 26, 2024 |
| Date Last Reviewed: | March 26, 2024 |
| Reasons: |
This shrew species appears to be limited to a very small, isolated area in the extreme northwestern corner of the province, found only in arctic tundra-like habitat in the Chilkat Pass area. Threats include climate change, however the overall impact is unknown. |
| Range | |
| Range Extent: | AB = <100-250 square km |
| Range Extent Comments: | Known from 3 occurrences near the Haines Road in the Chilkat Pass. Precise limits of its range extent are unknown. In 1983, a small mammal survey including pitfall trapping for shrews in alpine habitats west of the known occurrences in the Tashenshini area failed to detect this species (Royal BC Museum surveys) and this shrew may be restricted to arctic tundra-like habitat in the Chilkat Pass area. Known from the Chilkat Pass area up to Kelsall Lake in the northwestern corner of the province (Nagorsen and Jones 1981; Nagorsen 1996). |
| Area of Occupancy (km2): | CD = 3-25 |
| Area of Occupancy Comments: | Only 3 2x2 km grid cells are known to be occupied but with inventory more occupied areas are likely to be discovered. Much of the area in that corner of the province is unlikely to be occupied by the species due to topography and/or glaciation. |
| Occurrences & Population | |
| Number of Occurrences: | AB = 1 - 20 |
| Comments: | Only two known occurrences (5 specimens, 3 locations) in the Chilkat Pass area (Nagorsen and Jones 1981; Nagorsen 1996, Nagorsen and Panter 2024, GBIF 2023), but more may be found with more inventory. |
| Number of Occurrences with Good Viability / Ecological Integrity: | Rank Factor not assessed |
| Number of Occurrences Appropriately Protected & Managed: | B = 1 - 3 |
| Comments: | At least a portion of the known occurrences would be protected in Tatshenshini-Alsek Provincial Park. |
| Population Size: | U = Unknown |
| Comments: | Trapping results indicate that this is a rare species in British Columbia; only five specimens have been captured in several intensive surveys (Nagorsen 1996). |
| Threats (to population, occurrences, or area affected) | |
| Degree of Threat: | U = Unknown |
| Comments: |
Climate change and the possibility of increased shrub growth in the habitat along the Haines Road area is a potential threat. The three known occurrences in B.C. appear to be isolated from other populations in the Yukon and Alaska (Nagorsen and Panter 2024). Given the apparent rarity and isolation from other populations, development of habitat destruction in the intervening areas could place this species at greater risk. |
| Trend (in population, range, area occupied, and/or condition of occurrences) | |
| Short-Term Trend: | U = Unknown |
| Comments: | No trend data available; probably stable. |
| Long-Term Trend: | U = Unknown |
| Other Factors | |
| Intrinsic Vulnerability: | B=Moderately vulnerable |
| Comments: | According to Nagorsen and Jones (1981), the British Columbian population appears to be a highly isolated relict population separated from the nearest populations in Alaska and Yukon by ~ 500 km and beyond the distance for rescue effect. Recent surveys in southern Alaska and southern Yukon (Slough and Jung 2007; MacDonald and Cook 2009) have confirmed the isolation of the BC population. |
| Environmental Specificity: | Rank Factor not assessed |
| Other Rank Considerations: | |
| Information Gaps | |
| Research Needs: | |
| Inventory Needs: | Surveys should be conducted in areas of similar habitat to the east and south of the known occurrences to verify the isolated nature of this population and to determine the true extent of the Tundra Shrew's range in British Columbia. |
| Stewardship | |
| Protection: | |
| Management: | The present wilderness nature of the known occurrences should be maintained. Habitat preferences of this population should be studied, so that inventories can concentrate on appropriate habitat. |
| Version | |
| Author: | Ramsay, L. (2023), S. Cannings, L. Ramsay and A. Teucher (1998 and 2009) |
| Date: | December 30, 2023 |
| References | |
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Junge, J. A., R. S. Hoffman, and R. W. DeBry. 1983. Relationships within the Holarctic SOREX ARCTICUS-SOREX TUNDRENSIS species complex. Acta Theriologica 28:339-350.
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Nagorsen, D. 1990. The mammals of British Columbia: a taxonomic catalogue. Mem. No. 4. Royal B.C. Mus., Victoria. 140pp.
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Nagorsen, D. and N. Panter. 2024. Shrews and Moles of British Columbia. Second Edition. Royal BC Museum Handbook. 239 pp.
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Nagorsen, D.W. 1996. Opossums, Shrews and Moles of British Columbia. Royal B.C. Mus. Victoria, BC. 169pp.
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Nagorsen, D.W., and D.M. Jones. 1981. First records of the tundra shrew (Sorex tundrensis) in British Columbia. Can. Field-Nat. 95:93-94.
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Rausch, V. R., and R. L. Rausch. 1993. Karyotypic characteristics of SOREX TUNDRENSIS Merriam (Mammalia: Soricidae), a Nearctic species of the S. ARANEUS-group. Proc. Biol. Soc. Washington 106:410-416.
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Please visit the website Conservation Status Ranks for information on how the CDC determines conservation status ranks. For global conservation status reports and ranks, please visit the NatureServe website http://www.natureserve.org/.
Suggested Citation:
B.C. Conservation Data Centre. 2023. Conservation Status Report: Sorex tundrensis. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Jun 5, 2026).