White-nose syndrome is a fungal disease that has killed millions of bats across North America and threatens European bat populations, representing a severe wildlife welfare emergency.
WNS causes profound welfare suffering at individual and population scale. Infected bats experience repeated disruption of hibernation — waking to a cold environment with no food available, burning through fat reserves needed to survive winter. They are found outside hibernacula in freezing conditions, disorientated and starving. Death from starvation and hypothermia is slow. The scale of mortality — millions of animals — represents one of the most severe wildlife disease welfare crises in recorded history. Active research into protective treatments, including probiotic sprays and UV light decontamination, offers potential to reduce future mortality. Protecting remaining hibernation sites from human disturbance is the most immediately practical welfare action.