UK otters have recovered from near-extinction following pesticide bans, with ongoing welfare threats from road mortality, water pollution, and habitat loss.
Road casualties cause acute trauma and death for individual otters - often the most productive adults in established territories. Mortality of breeding individuals can leave dependent cubs to starve. The pattern of otter recovery demonstrates how removing the primary welfare threat - organochlorine poisoning - allows population recovery. Addressing secondary threats including road mortality through otter bridges and culvert ledges maintains the welfare gains from pesticide banning.