The International Union for Conservation of Nature (IUCN) Red List of Threatened Species numbers 147,517 species, including 41,459 that are threatened with extinction. The latest update adds the migratory monarch butterfly, a subspecies of the monarch butterfly (Danaus plexippus). In the past decade, the native population has shrunk by between 22 percent and 72 percent during winter migrations from Mexico and California to summer breeding grounds throughout the U.S. and Canada due to logging and deforestation for agriculture and urban development. Pesticides and herbicides kill butterflies and milkweed, the host plant that the larvae of the monarch butterfly feed on. Drought related to climate change limits the growth of milkweed and increases the frequency of catastrophic wildfires, and temperature extremes trigger earlier migrations before milkweed is available, while severe weather has killed millions of butterflies.

Possible remedies are planting native milkweed, reducing pesticide and protecting the overwintering sites. IUCN Director General Dr. Bruno Oberle says, “To preserve the rich diversity of nature, we need effective, fairly governed, protected and conserved areas alongside decisive action to tackle climate change and restore ecosystems. In turn, conserving biodiversity supports communities by providing essential services such as food, water and sustainable jobs.”