Vole and Shrew Welfare: Small Mammals in the Trap and the Food Chain

Voles and shrews are among the most numerous UK mammals but face welfare challenges from agricultural practices, predation, and use in small mammal research.

Key Facts

Water voles have declined by 95% in the UK since the 1970s, primarily due to mink predation
Field voles are the most numerous UK mammal with population peaks of 75 million animals
Shrews have the highest metabolic rate of any mammal and must eat every few hours to survive
Small mammal research frequently uses live-trap-and-release methods that cause significant stress
Agricultural practices including ploughing and silage cutting kill enormous numbers of small mammals
Barn owls depend critically on vole populations, linking small mammal welfare to owl conservation

Welfare Considerations

Live trapping of small mammals for research purposes — even Longworth traps considered standard practice — subjects animals to prolonged confinement in stressful conditions. Shrews caught in traps frequently die from the metabolic stress of confinement. Silage cutting across fields kills enormous numbers of field voles through mechanical injury — an ecologically invisible but massive welfare event. Water voles killed by American mink suffer predatory deaths; mink control programmes (trapping and killing) create their own welfare considerations. The extreme metabolic needs of shrews mean any disruption to foraging patterns causes rapid deterioration.

What You Can Do

Support water vole recovery programmes including mink control in vole conservation areas
Advocate for silage cutting practices that include pre-cut flushing to reduce small mammal mortality
Encourage research institutions to adopt refinements to small mammal trapping protocols
Create small mammal habitat in gardens through log piles, long grass, and wildlife corridors