The rarest of the rare – protecting critically endangered butterflies

The rarest butterflies in the United States, and in the world, hold lessons about threats, recovery, and conservation that extend to other insects. The rarest butterflies typically number into the low thousands, and their ranges extend just a few hectares. Measured over decades, their numbers are generally set on a downward trajectory. The rarest butterflies are always threatened by habitat loss. But this threat is often coupled with others, including climate change, invasive species, and pollution. The rarest butterflies often live on the edge in dynamic environments, where disturbance from weather or fire imposes short term losses, but is needed for long-term population persistence. Viewed across species, populations of the rarest insects have proven fragile in the face of their changing environment, but can demonstrate resilience only when properly managed in conservation.