Welfare of Monarch Butterflies During Migration

Monarch butterfly migration is one of nature's most remarkable journeys — and one of its most threatened.

Key Facts

Monarch butterflies migrate up to 4,500 km from Canada and the US to Mexico annually
Western monarch populations have declined over 99% since the 1980s
Loss of milkweed — their sole larval food plant — from agricultural herbicide use is the primary driver
Oyamel fir forests in Mexico where monarchs overwinter are threatened by logging

Welfare Considerations

Monarch butterfly welfare is uncertain — whether butterflies experience morally relevant suffering is not established. However, the ecological and conservation dimensions of monarch decline are profound: as a pollinator and prey species, monarch decline affects the many sentient animals that depend on healthy insect ecosystems. Milkweed loss from glyphosate herbicide use in agricultural fields has decimated caterpillar food availability. Restoring milkweed along migration corridors is one of the most accessible conservation actions available to individual landowners.

What You Can Do

Plant native milkweed species in your garden to support monarch breeding
Avoid herbicide use that eliminates milkweed from agricultural edges
Support overwintering forest protection in Mexico
Engage with the pollinator garden movement as a wildlife welfare action