Monarch butterfly populations have declined dramatically due to milkweed loss, pesticides, and climate change. Their long migration and the welfare implications of population collapse make them a significant welfare concern.
Monarch butterfly welfare exists at the intersection of individual insect welfare uncertainty and ecological crisis. Whether monarchs can suffer in a morally relevant sense remains debated, but sublethal pesticide effects on navigation and reproduction demonstrate clear functional impairment. The ecological collapse of monarch populations removes a keystone pollinator from ecosystems, with cascading welfare implications for species that depend on the plants monarchs pollinate. Habitat restoration through milkweed planting is the most direct individual action available.