The painted lady butterfly undertakes the longest known insect migration, crossing the Sahara Desert twice annually, with welfare implications for individual insects during this extraordinary journey.
The welfare of insects during migration raises genuinely novel questions. Individual painted ladies crossing the Sahara Desert face dehydration, starvation, and exhaustion, and many perish on the crossing. Predation by birds along migration routes causes rapid mortality for individual butterflies. Whether painted ladies experience suffering in a morally significant sense remains uncertain, but growing research on insect nociception and learning warrants increasing consideration of invertebrate welfare at population scale. The welfare and conservation implications of climate change altering Saharan crossing conditions are an emerging area of concern.