On an early morning in 1975, H. Douglas Pratt awoke in his tent pitched on Hawaii’s Alakaʻi Plateau to the song of the Kauaʻi ʻŌʻō. The bell-like vocal clarity was unmistakable, though the bird was extremely rare; the species was listed as federally endangered in 1973, with an estimated population of 36 surviving individuals. “I can still recall the hair standing up on my neck,” the retired ornithologist says. “Their song can be described as both haunting and evocative.” Pratt was lucky to hear the Kauaʻi ʻŌʻō, and was one of the last people to do so. The mostly black bird with tufts of striking yellow feathers on its thighs was last seen in 1985 and last heard in 1987. No one will ever hear it sing in the wild again. On Wednesday, the U.S. Fish and Wildlife Service (USFWS) declared 23 species across the United States extinct and proposed they lose protections under the Endangered Species Act (ESA). Eight of those species, including the Kauaʻi ʻŌʻō...