White-nose syndrome, caused by the fungus Pseudogymnoascus destructans, has killed over 6 million North American bats since 2006. Understanding this crisis and its welfare dimensions is essential for bat conservation.
White-nose syndrome causes suffering at a scale that is difficult to comprehend. Individual bats dying from WNS experience prolonged starvation after premature arousal exhausts their hibernation fat reserves — a slow, debilitating death over days to weeks. The population-level welfare implications are staggering: millions of individuals dying annually across multiple species. Hibernation is ordinarily a period of physiological quiescence during which bats are largely insensible, but the repeated arousals caused by fungal irritation bring them to a semi-alert state in which they respond to their condition and environment. The ecological welfare implications extend beyond bats: the loss of major insectivore populations has increased insect pest pressure on crops, leading to increased pesticide use that further harms wildlife.