Invertebrate Welfare

Wild Monarch Butterfly Population Decline

Monarch butterfly populations have declined dramatically due to milkweed loss, pesticides, climate change, and deforestation of overwintering sites.

Key Facts

Western monarch populations have declined over 99 percent since the 1980s
Monarchs depend entirely on milkweed plants for breeding
Overwintering colonies in Mexico span just a few hectares
Climate change disrupts migration timing and weather during overwintering

Welfare Considerations

Population collapses reduce individual welfare through overcrowded overwintering sites, inadequate food resources during migration, and exposure to extreme weather. Climate disruption creates mismatch between migration cues and available resources, causing energy depletion and mortality.

What You Can Do

Plant native milkweed and nectar plants in your garden
Avoid pesticides especially neonicotinoids
Support overwintering habitat conservation in Mexico
Report monarch sightings to citizen science tracking programs