White-nose syndrome (WNS), caused by the fungus Pseudogymnoascus destructans, has killed over 90% of some North American bat species. It causes suffering on an enormous scale and remains a severe ongoing threat.
Individual bats with WNS experience disrupted hibernation, energetic exhaustion from repeated arousal, and ultimately starvation and death in winter conditions. The scale of mortality - millions of animals - represents one of the largest wildlife disease welfare crises in recorded North American history. Research on probiotic treatments, antifungal interventions, and genetic resistance offers hope. Cave closures during bat hibernation season reduce human introduction of the fungus and protect hibernating populations from disturbance that compounds WNS stress.