Well, this sucks

 The population of western Monarchs dropped 99% between 1980s and 2021. The population of the eastern Monarchs dropped 84% between 1996 and 2021.

It sucks for many people who love(d) the migration and saw hundred of thousands travel to Mexico every year.

From the NY Times:

North America’s monarch butterfly, whose showy looks and extraordinary migration have made it one of the continent’s most beloved insects, has been classified as endangered by the International Union for Conservation of Nature, the world’s most comprehensive scientific authority on the status of species.

The decision comes after decades of falling populations driven by losses in the plants they need as caterpillars and in the forests where adults spend the winter, combined with climate change, the assessment found. The authors reviewed about 100 studies, interviewed experts and applied criteria from the group’s Red List of Threatened Species to come up with their decision.

The numbers of Western monarchs, which live west of the Rocky Mountains, plummeted by an estimated 99.9% between the 1980s and 2021. While they rebounded somewhat this year, they remain in great peril. Eastern monarchs, which make up most of the population in North America, dropped by 84% from 1996 to 2014. The new designation of endangered covers both populations.