Monarch butterflies undertake one of the most remarkable migrations on Earth, but their populations have collapsed by over 90%. While insect sentience is uncertain, the precautionary principle and ecological stakes make their welfare worth considering.
The case for monarch welfare is precautionary given scientific uncertainty about insect sentience. What is clear is that the scale of population collapse represents an enormous reduction in the number of animals completing a remarkable life cycle. Pesticide deaths likely cause some form of distress based on behavioral responses observed. Habitat destruction prevents completion of the multi-generational migration, causing population-level suffering regardless of individual experience. Regardless of where one stands on insect sentience, supporting monarch conservation reduces harm at scale and preserves one of nature's most extraordinary phenomena.