British bats are exclusively insectivorous and their welfare is directly linked to invertebrate prey availability, which is declining across agricultural landscapes.
Bat welfare is primarily an insect availability problem: bats that cannot catch sufficient prey during the summer lactation season cannot raise viable pups or accumulate enough fat for winter hibernation. The decline of insect biomass across agricultural landscapes means chronic nutritional stress for bat populations dependent on farmland foraging. Individual bats experiencing this stress show reduced reproductive success, thinner pups, and increased winter mortality. Habitat management that maintains insect communities — reducing pesticide use, maintaining hedgerows and woodland — directly improves bat welfare outcomes.