Water Shrew Watch

With a black upper side, smartly contrasting with a white throat and belly, they are the most distinctive of all our small mammal species. Despite this, they are seldom seen.

A fascinating and challenging animal

As the name implies, Water Shrews like wetlands. They are occasionally found away from water, but usually live in and alongside rivers, burns and ponds. Here, they dive underwater, to catch aquatic invertebrates, so they can be a good indicator of water quality. They also have poisonous saliva, so can incapacitate larger prey items, such as amphibians.

As a species considered to be Locally Important, we are keen to find out more about their status in the North East. Most earlier Water Shrew records in the North East were chance encounters, with a few from close analysis of droppings. Recently there has been an upsurge in records from camera trapping.

Camera traps are not designed for monitoring small mammals, but we’ve obtained great results by strapping a camera with close-focus lens to a box, bating with mealworms and leaving in a likely place. In the process, we’ve found Water Shrews in Beechgrove Garden (of TV fame), along coastal ditches and up into moorland burns. Two Aberdeen University students surveyed 60 sites with cameras in 2017 and found Water Shrews at 12 of them. Others volunteer recorders have used camera traps to find Water Shrews from Portlethen Moss to Forest of Birse and beyond.

This has all been timely, as we contributed new site records for the Mammal Atlas of North-East Scotland and the Cairngorms. Records continued to come in after 2015, when recording for the atlas concluded. Now, we have Water Shrew records from 64 tetrads (2 × 2 km squares) across the North East and that number grows each year.

Water Shrew distribution map

Water Shrew distribution map

We think Water Shrews rock, and this has led us to develop Water Shrew Watch. We’d like to know more still about where they live in the region – for example, how high they go, or if they are absent from some catchments. Ongoing recording can also reveal long-term responses to habitat change, or alterations in water quality. If you want to join this citizen science initiative, camera trapping is certainly the easiest way. Cameras trained on the water’s surface can detect their hyperactive skimming around between dives. And we have found that the use of mammal camera trap boxes greatly enhances the success rate of detecting these enigmatic creatures. Finally, remember to make your records count and send them to North-East Scotland Biological Records Centre.

Rose Toney

Coordinator at The Biodiversity Partnership (2010-2019)