Wild Bat White-Nose Syndrome | Animal Welfare Hub

White-nose syndrome is a devastating fungal disease that has killed over 6 million North American bats since 2006, causing immense population-level suffering and ecological disruption.

Key Facts

White-nose syndrome (WNS) is caused by the fungus Pseudogymnoascus destructans, introduced from Europe where bats have evolved resistance
Mortality rates from WNS reach 90-100% in some hibernating bat colonies — little brown bat populations have declined by over 90% in affected areas
The fungus grows on bat wings and muzzle during hibernation, disrupting thermoregulation and causing bats to arouse repeatedly
Repeatedly aroused bats deplete fat reserves and die of starvation, dehydration, and exhaustion during winter
Affected bats exhibit distinctive erratic daytime flight behavior in winter — they are starving and desperately seeking food
WNS has spread to 38 US states and 7 Canadian provinces since first detected in a New York cave in 2006
A probiotic bacterial treatment (Pseudomonas fluorescens) shows promise in trials, reducing fungal growth on treated bats

Welfare Considerations

White-nose syndrome causes prolonged suffering at massive scale. Affected bats spend winter in repeated arousal cycles — each awakening burns desperately needed fat reserves. As the season progresses, bats become thin, weakened, and ultimately fly out of caves in winter weather in a final desperate search for food. This dying behavior — visible in staggering, daylight-flying bats in January and February — represents the endpoint of weeks of progressive starvation. The ecological consequences compound the welfare tragedy: insectivorous bats consume vast quantities of agricultural pests, and their collapse increases pesticide demand. Research into probiotic treatments, vaccine development, and cave decontamination protocols offers hope. Cave visitor decontamination protocols — cleaning gear between sites — remain essential to prevent further spread.

What You Can Do

Decontaminate all caving equipment between cave visits — follow White-Nose Syndrome decontamination protocols from whitenosesyndrome.org
Install bat boxes on your property to provide supplemental roosting habitat for recovering bat populations
Support Bat Conservation International and the White-Nose Syndrome Response Team with donations
Reduce pesticide use in gardens and on farms — insect availability is critical for bat foraging recovery
Report sick or dying bats in winter to state wildlife agencies — surveillance data helps track WNS spread