The pygmy shrew is the smallest mammal in Britain and one of the smallest in the world, requiring dense ground vegetation and abundant invertebrates to fuel its extraordinarily rapid metabolism.
Pygmy shrews face welfare challenges primarily from habitat degradation that reduces invertebrate prey availability. Agricultural intensification, removal of rough grassland and hedgerows, and the use of pesticides all reduce the density of small invertebrates on which they depend. Their short lifespan means population recovery from habitat loss events is possible but requires sustained habitat quality. Climate variability affects prey availability and can cause acute starvation events during cold spells.