White-nose syndrome, caused by the fungus Pseudogymnoascus destructans, has killed over 7 million North American bats since 2006 in one of the fastest wildlife declines ever recorded.
Bats affected by white-nose syndrome wake from hibernation in mid-winter, fly out into cold conditions without adequate fat reserves, and starve or freeze. The death process involves emaciation, exhaustion, and cold exposure. The scale of mortality represents billions of individual animals dying in distress. Beyond individual suffering, bat population collapse reduces insect control services worth an estimated 23 billion dollars annually to US agriculture, with cascading ecological effects on the plants and animals bats support.