The greater horseshoe bat is one of Britain's rarest mammals, with welfare challenges from roost disturbance, pesticide reduction in prey and loss of grassland foraging habitat.
Greater horseshoe bats are highly sensitive to roost disturbance: entry during the maternity season causes pup abandonment and hypothermia in newborns. Reduction in large flying insects — particularly dung beetles, chafers and moths — caused by pesticide use and intensification of grassland management reduces foraging success, leading to reduced body condition before hibernation. Poor pre-hibernation condition increases overwinter mortality.