What do the nēnē goose, American peregrine falcon, El Segundo blue butterfly, Robbins’ cinquefoil, and bald eagle have in common? Once verging on extinction, they are all either steadily improving or have been removed from the list of endangered species. Most credit the Endangered Species Act passed by Congress in 1973. Ninety percent of species protected by the act are recovering at the rate specified by their federal recovery plan, according to a 2012 study by the Center for Biological Diversity, an Arizona-based nonprofit.
The work isn’t over. Today there are still 2,054 species worldwide listed as endangered or threatened, according to the US Fish and Wildlife Service.
