White-nose syndrome, caused by a fungal pathogen, has devastated North American bat populations and threatens European bats, representing a massive wildlife welfare crisis.
White-nose syndrome causes prolonged and distressing death in affected bats. The fungus irritates skin during hibernation, causing bats to rouse frequently to scratch and groom, depleting fat reserves needed to survive winter. Affected bats emerge in winter in daylight when there are no insects to feed, starving and freezing in the open. Population crashes following white-nose syndrome devastate communities that rely on bats for insect pest control. Welfare responses include monitoring, probiotic treatments applied to cave environments, and research into vaccine approaches. The scale of bat mortality represents one of the most significant wildlife welfare events in recent history.