BC Conservation Data Centre: Conservation Status Report
Sorex palustris
American Water Shrew
| Scientific Name: | Sorex palustris |
|---|---|
| English Name: | American Water Shrew |
| English Name Synonyms: |
Common Water Shrew
|
| Provincial Status Summary | |
| Status: | SU |
| Date Status Assigned: | April 29, 2024 |
| Date Last Reviewed: | April 29, 2024 |
| Reasons: | There are only two documented occurrences in the north east portion of the province (one historical), however there are large unsampled areas with appropriate habitat around where this species is found. There are threats in the range, however unquantifiable without further surveys to know the species' extent and therefore threat impact. |
| Range | |
| Range Extent: | E = 5,000-20,000 square km |
| Range Extent Comments: | There are two known specimens from B.C. that occur close to the Alberta border, one from Kotcho Lake in 1982, the other a historical record from 1938 found near Tupper Creek (Nagorsen and Panter 2018, Nagorsen and Panter 2024). Surveys for shrews done for the Site C hydroelectric dam in the Peace River area did not find any water shrews, but other than this effort there have been few surveys for shrews, particularly known to have occurred in appropriate habitat (Nagorsen and Panter 2024). Nagorsen (pers. comm) suggests that it will very likely be found to the east and through the Peace River area. |
| Area of Occupancy (km2): | U = Unknown |
| Occurrences & Population | |
| Number of Occurrences: | AC = 1 - 80 |
| Comments: | Although there are only two currently (2024) known locations (and one is historical), there has been limited survey effort in that part of the province and it is predicted to be found in more locations (Nagorsen and Panter 2024, Nagorsen, pers. comm.). Access to the northern portion of the range is limited. |
| Number of Occurrences with Good Viability / Ecological Integrity: | Rank Factor not assessed |
| Number of Occurrences Appropriately Protected & Managed: | Rank Factor not assessed |
| Population Size: | U = Unknown |
| Threats (to population, occurrences, or area affected) | |
| Degree of Threat: | U = Unknown |
| Comments: | There are habitat changes and increased pollutants in this region from oil and gas exploration, flooding and deforestation from the Site C dam construction, forest harvesting and agricultural development, all potential threats to this wetland dwelling species. The range is uncertain as are the number of locations making quantification of the threats difficult. |
| Trend (in population, range, area occupied, and/or condition of occurrences) | |
| Short-Term Trend: | U = Unknown |
| Long-Term Trend: | U = Unknown |
| Other Factors | |
| Intrinsic Vulnerability: | Rank Factor not assessed |
| Environmental Specificity: | B=Narrow. Specialist or community with key requirements common. |
| Comments: | Strongly tied to wet habitats (Nagorsen 1996). |
| Other Rank Considerations: | |
| Information Gaps | |
| Research Needs: | |
| Inventory Needs: | Yes |
| Stewardship | |
| Protection: | |
| Management: | |
| Version | |
| Author: | Ramsay, L. (2024), Nagorsen, D. and L. Ramsay (2015) |
| Date: | January 02, 2024 |
| References | |
|
Nagorsen, D. and N. Panter. 2018. Evidence for the Occurrence of the American Water Shrew (Sorex palustris) in British Columbia. Unpublished report. 12 pp (including appendices).
|
|
|
Nagorsen, D. and N. Panter. 2024. Shrews and Moles of British Columbia. Second Edition. Royal BC Museum Handbook. 239 pp.
|
|
|
Nagorsen, D.W. 1996. Opossums, Shrews and Moles of British Columbia. Royal B.C. Mus. Victoria, BC. 169pp.
|
|
|
O'Neill, M.B., D.W. Nagorsen, and R.J. Baker. 2005. Mitochondrial DNA variation in water shrews (Sorex palustris, Sorex bendirii) from western North America: implications for taxonomy and phylogeography. Can. J. Zool. 83:1469-1475.
|
|
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. 2024. Conservation Status Report: Sorex palustris. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Jun 13, 2026).