Nearly two dozen species are being taken off the endangered species list because they are extinct, the U.S. Fish and Wildlife Service said Monday.

Most of the species were listed under the Endangered Species Act in the 1970s or 1980s and were very low in numbers or likely already extinct at the time of listing. In the years since, “rigorous reviews of the best available science” have been conducted to determine whether the animals are extinct.

“Federal protection came too late to reverse these species’ decline, and it’s a wake-up call on the importance of conserving imperiled species before it’s too late,” Service Director Martha Williams said.