Fourth article: Searching for stoats & wondering about weasels

Searching for stoats and wondering about weasels

When was the last time you saw a stoat or a weasel? Maybe a fleeting glimpse of one dashing across the road? Or if you’re very lucky, a view of a stoat carrying a rabbit along a field edge?

Stoats and weasels are part of the mustelid, or weasel, family. They occur all across Britain but are among our hardest mammal species to study. Monitoring them has proved challenging as they do not leave easily visible field signs, are generally elusive and rarely seen and, like many mammal species, are probably under-recorded. Without robust and reliable monitoring methods, it is almost impossible to collect any data on the species.

Despite being thought to be common and widespread, very little is known about weasels and stoats in Britain and specifically, almost nothing is known about their abundance and population trends. There have been some suggestions that populations of stoats and weasels may be declining but there are currently no methods to determine population trends with any degree of accuracy. This is particularly pertinent in light of the recent discovery that rabbits, which make up a large proportion of the stoat’s diet, are declining in Britain and it’s not known how this may affect stoat populations. The Vincent Wildlife Trust (VWT) is keen to establish which monitoring methods work successfully and can be used to gather reliable data on both species.

The VWT is currently testing a detection device called the ‘Mostela’ which was designed by the Dutch Small Mustelid Foundation. It has been used successfully in the Netherlands to detect weasels, stoats and the occasional polecat. The ‘Mostela’ comprises a wooden box with a plastic tunnel running through it and a camera inside, trained on the tunnel. When an animal enters the tunnel, the camera is triggered and records a video or photo. Mostelas are generally positioned under hedgerows, along walls and other linear features, where small mustelids are likely to be moving through the landscape. The VWT is in the process of trialling the Mostelas at a variety of sites across the country and look forward to seeing what we find. Watch this space!

Next time you see a stoat or weasel, be sure to record your sighting using either The Mammal Society’s Mammal Tracker app or contacting your Local Biological Records Centre.

Lizzie Croose, VWT’s Senior Carnivore Conservation Officer