Searching for Shrews

Searching for Shrews - Mammal Society

The GWT shrew is a new non-native species in Britain and might become invasive, affecting native shrews
DNA sampling is being planned to be able to answer where it originated from
Mammal Society and MammalWeb are calling for increased monitoring of small mammals, in particular shrews, in Britain
Since the first press release, another likely GWT shrew has been identified in Nottinghamshire from photographs taken of a dead specimen earlier this year. Indicating that monitoring of shrews should be at national extents.

In September 2022, the Greater White-toothed (GWT) shrew was discovered in Great Britain by Ian Bond, from a specimen caught by Melissa Young’s indoor cat. This new non-native mammal, found in the Sunderland area, was confirmed via a DNA test undertaken by Ecotype Genetics and Swift Ecology Ltd.

At present, the GWT shrew is not known to be invasive in Britain but, as a new non-native species, it has the ability to become invasive. The GWT shrew is known to outcompete the pygmy shrew in Ireland and there is a possibility that the GWT shrew will negatively affect, or completely displace our pygmy shrew.

“When the species was first found in Ireland in 2007, we thought that it could be a positive addition and maybe act as a new and plentiful prey source for birds of prey and other carnivores.” said Allan McDevitt of the Mammal Society. “However, we soon realised that the native pygmy shrew had completely disappeared whenever the GWT moved into an area. Obviously, we are concerned about similar problems occurring in Britain.”

The GWT shrew is native to Europe, North Africa and some of the Channel Islands. Although the origins of the shrews found in Sunderland are currently unknown, they could have been imported from Ireland or the European continent. DNA sampling is being planned to be able to answer this question.