Monarch butterfly populations have collapsed dramatically, with individual welfare implications from habitat loss, pesticides, and climate disruption along their migration route.
While insect sentience remains scientifically uncertain, the precautionary principle supports concern for monarch welfare given the scale of population collapse. Individual butterflies face increased energetic stress from depleted nectar sources along migration routes, pesticide exposure, and disruption of overwinter clustering habitat in Mexico. The welfare of any sentient capacity they have is directly threatened by habitat degradation and climate change.