This fascinating creature can literally walk on water! Air bubbles trapped beneath the unique fringe hairs of the feet provide enough buoyancy to enable them to run on the surface of the water for up to 5 seconds! Federally endangered and provincially red-listed, the Pacific Water Shrew is at risk due to destruction of its wetland and riparian habitat.
Even with intensive survey effort, this elusive mammal is near impossible to find. A recent rigorous survey effort in the Fraser Valley, had biologists monitoring 50 traps, 24 hours a day for 2 weeks, and resulted in the capture of a single individual! This species has yet to be confirmed present on the Sunshine Coast but has been detected in nearby Squamish.
How We are Helping Water Shrews
We are using environmental DNA (eDNA) sampling to look for this rare species at risk. As they go about their daily lives, all animals leave behind traces of their DNA in their environment, through skin cells, urine, feces, blood and gametes. Known as environmental DNA, these genetic traces can be used to detect the presence of species within ecosystems. Recent studies have demonstrated the efficacy of eDNA as an exciting new technique to detect presence of wildlife in freshwater ecosystems. The method has proven to be highly accurate, efficient, and cost effective. The technique is highly sensitive so can detect species even when they exist in very low density.
Over the past two years, we have used eDNA sampling to search for Pacific Water Shrews. We have been pleased to collaborate with Hemmera, the BC Ministry of Environment, and Dr. Caren Goldberg at Washington State University, to contribute to the development and testing of an eDNA primer for Pacific Water Shrew. In the coming years, we look forward to continuing to use this exciting new technique to search for rare, elusive and difficult to sample species in other regions of the Sunshine Coast.
- Status Report on Pacific Water Shrew in Canada
- Pacific Water Shrew (South Coast Conservation Program)