Length 13.7-17.9 cm (including 7cm tail), Weight 10-20 g. In North America this is the largest shrew in the genus Sorex. Fur (pelage) is a velvety dark-brown to black, only slightly paler on the ventral area than on the dorsal area; more brownish in summer than winter. The dark brown tail is uni-coloured. The pelage has a dual ability to repel water while trapping a layer of air. This acts as an insulation layer reducing heat loss by 50% while swimming (critical as most shrew species have a high metabolic rate and can stress from energy loss quickly). The skull is large with a ventrally curved rostrum (area where the snout extends from the top of the skull) and holds 32 teeth. As their name implies, Pacific Water Shrew are excellent swimmers. Air bubbles trapped beneath the unique fringe hairs of the front and hind feet provide enough buoyancy to enable them to run on the surface of the water for up to 5 seconds.
British Columbia’s Coast Region Species and Ecological Communities of Conservation Concern SPECIES PROFILE: Pacific Water Shrew (Sorex bendirii), Family Soricidae (“shrews”)
BC Conservation Data Centre. 2015. [Internet] [Updated December 2009] Conservation Status Report: Sorex bendirii. BC MoE. - BC Conservation Data Centre. 2015. [Internet] Species Summary: Sorex bendirii. BC Ministry of Environment. Catania Kenneth C. et al. 2008. [Internet]. Water shrews detect movement, shape, and smell to find prey underwater. Proceedings of The National Academy of Sciences of the USA. PNAS vol. 105 no. 2 pp. 571–576. - BC Ministry of Water, Land and Air Protection. 2004. [internet] Accounts and Measures for Managing Identified Wildlife. Version 2004. Biodiversity Branch, Identified Wildlife Management Strategy, Victoria, BC. COSEWIC. 2006. [Internet] COSEWIC assessment and update status report on the Pacific water shrew Sorex bendirii in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. vi + 28 pp. - Craig, Vanessa and Ross Vennesland. 2010. [draft] Best Management Practices Guidelines for the Pacific Water Shrew in Urban and Rural Areas. Prepared for the BC Ministry of Environment. Victoria (BC). - Craig, Vanessa. 2007. [Internet] Habitat Suitability/Capability Modeling for Pacific Water Shrew. Prepared for the BC Ministry of Environment Surrey (BC). - Craig, Vanessa. 2007. [Internet] Species Account and Preliminary Habitat Ratings for Pacific Water Shrew (Sorex bendirii) Using TEM Data v. 2. Prepared for the BC Ministry of Environment Surrey (BC). - Environment Canada. 2014. Recovery Strategy for the Pacific Water Shrew (Sorex bendirii) in Canada. Species at Risk Act Recovery Strategy Series. Environment Canada, Ottawa. 35 pp. + Appendix. - Proulx, Gilbert et al. 2003. A Field Guide to Species at Risk in the Coast Forest Region of British Columbia. Published by International Forest Products and BC Ministry of Environment. Victoria (BC). Welstead, Kym, and Ross Vennesland. 2006. [Internet] Fish Traps Threaten Pacific Water Shrew Recovery. Streamline Watershed Management Bulletin Vol. 9/No. 2 Spring 2006. - Zuleta, G.A. and C. Galindo-Leal. 1994. Distribution and Abundance of Four Species of Small Mammals at Risk in a Fragmented Landscape. Ministry of Environment, lands and Parks Wildlife Working Report No. WR-64.
Species Profile prepared by: Pamela Zevit with Kym Welstead (FLNRO) for the South Coast Conservation Program (SCCP) in partnership with: International Forest Products (Interfor), Capacity Forestry (CapFor). Funding was made possible through the Sustainable Forestry Initiative (SFI): http://www.sfiprogram.org/
Updated and revised by: Isabelle Houde, RPBio in consultation with the SCCP. Part of the National Conservation Plan, this project was undertaken with the financial support of the Government of Canada. Dans le cadre du Plan de Conservation National, ce projet a été réalisé avec l’appui financier du Gouvernement du Canada.
Every effort has been made to ensure content accuracy. Comments or corrections should be directed to the South Coast Conservation Program: firstname.lastname@example.org. Content updated March 2015.
Image Credits: Pacific Water Shrew: Denis Knopp, Pacific Water Shrew hind foot: Mike McArthur, American Water Shrew:Chris Lee, Habitat: Pamela Zevit. Only images sourced from “creative commons” sources (e.g. Wikipedia, Flickr, U.S.Government) can be used without permission and for non-commercial purposes only. All other images have been contributed for use by the SCCP and its partners/funders only.