The monarch butterfly's annual migratory journey from Mexico to the U.S. and then Canada is a breeze compared to the federal government's lengthy process to protect the dwindling species. Why it matters: The monarch — whose population has declined more than 80% since the 1990s — has waited more than 10 years for protection under the Endangered Species Act.

The Trump administration is reopening public comment on a proposed rule that would list the monarch butterfly as threatened under the Endangered Species Act.

In a turn of events, the eastern monarch butterfly population — which was put on the list of endangered species just a few years ago — nearly doubled this year, according to a March report from the World Wildlife Fund,