Amphibians are experiencing the fastest mass extinction of any vertebrate class, with Batrachochytrium dendrobatidis fungus alone having caused over 90 species extinctions and hundreds of population collapses.
Chytrid fungus kills amphibians through disruption of their skin which is their primary respiratory and osmoregulatory organ. The fungal infection causes electrolyte depletion and cardiac arrest - a death that takes days and likely involves significant physiological distress as essential bodily functions fail. Habitat destruction leaves amphibians in fragmented patches with insufficient resources for survival. Invasive predators consume entire breeding populations. Climate disruption causes breeding attempts at wrong times relative to food availability, leaving tadpoles to starve. If amphibians have welfare relevant experiences, the ongoing collapse of 41 percent of species represents welfare harm at an almost incomprehensible scale - a multi-species extinction crisis playing out across every continent.