The ivory-billed woodpecker, which bird watchers have been searching for in the Arkansas swamps, is gone forever, according to federal officials. So is the Bachman’s Warbler, a yellow-breasted songbird that once migrated between the southeastern United States and Cuba. The song of the Kauai O’o, a Hawaiian forest bird, only exists on recordings. And there is no longer hope for various types of freshwater mussels that once filtered streams and rivers from Georgia to Illinois.
In all, 22 animals and one plant should be declared extinct and removed from the endangered species list, federal wildlife authorities said Wednesday.
The announcement could also offer a glimpse of the future. It comes amid a global biodiversity crisis that worsens than threatens a million species with extinction, many in decades. Human activities such as agriculture, logging, mining, and dam building take over the habitat of animals and pollute much of what remains. People poaching and overfishing. Climate change adds new dangers.
“Each of these 23 species represents a permanent loss to our nation’s natural heritage and global biodiversity,” said Bridget Fahey, who oversees species classification for the Fish and Wildlife Service. “And it’s a sobering reminder that extinction is a consequence of human-caused environmental change.”
The extinctions include 11 birds, eight freshwater mussels, two fish, a bat, and a plant. Many of them were likely extinct, or nearly extinct, when the Endangered Species Act was passed in 1973, officials and advocates said, so perhaps no amount of conservation could have saved them..
“The Endangered Species Act was not passed in time to save most of these species,” said Noah Greenwald, director of endangered species at the Center for Biological Diversity, a nonprofit group. “It’s a tragedy”.
Since the law was passed, 54 species in the United States have been removed from the endangered list because their populations rebounded, while another 48 have improved enough to go from endangered to threatened. So far, 11 species included in the list have been declared extinct.
A 60-day public comment period begins on Thursday on the new batch of 23. Scientists and the general public can provide the information they would like the Fish and Wildlife Service to consider before making a final decision.
Without conservation, scientists say, many more species would have disappeared. But with humans transforming the planet so drastically, they add, much more needs to be done.
“Biodiversity is the foundation of social and economic systems, but we have not been able to solve the extinction crisis,” said Leah Gerber, ecologist and director of the Center for Biodiversity Outcomes at Arizona State University.
Next month, talks on a new global biodiversity deal will intensify. One proposal that has gained traction recently is a plan, known as 30×30, to protect at least 30 percent of Earth’s land and oceans by 2030.
Scientists don’t declare extinctions lightly. Decades of fruitless searching are often required. About half of the species in this group are already considered extinct by the International Union for Conservation of Nature, the world’s authority on the status of animals and plants. The Fish and Wildlife Service moved slower in part because it is working behind schedule, officials said, and tends to prioritize protecting species that need it over removing protection for those that don’t.
Many of the final confirmed sightings were in the 1980s, although one Hawaiian bird was last documented in 1899 and another in 2004.
No animal in the lot has been more passionately sought out than the ivory beak, the largest woodpecker in the United States. Once they inhabited ancient forests and swamps in the southeast, the birds declined as European settlers and their descendants cleared the forests and hunted them. The last confirmed sighting was in Louisiana in 1944.
But in 2004, a kayaker named Gene Sparling started a flurry of searches when he spotted a woodpecker that looked like an ivory bill in an arkansas swamp. Days after learning of it, two seasoned bird watchers, Tim Gallagher and Bobby Harrison, flew out to join him on a search. On day 2, paddling in their kayaks, they were preparing to stop for lunch when suddenly a large bird flew in front of them. “Tim and I yelled ‘Ivory-bill!’ at the same time, ”Mr. Harrison recalled.
In doing so, they drove the bird away.
A host of Cornell University ornithologists, several more searches, a few reported sightings, and a fuzzy video later, a 2005 article in Science magazine stated “The ivory-billed woodpecker (Campephilus principalis) persists in continental North America”.
Controversy continued. Some the experts argued that the footage was of stacked woodpeckers. Repeated attempts by state and federal wildlife agencies to find the bird have been unsuccessful, and many experts have concluded that it is extinct.
When Amy Trahan, a biologist with the Fish and Wildlife Service, completed the most recent species assessment for the woodpecker, she said, she had to make her recommendation based on the best available science. At the end of the report, he marked a line next to the words “remove from list based on extinction.”
“That was probably one of the hardest things I’ve ever done in my career,” he said. “I literally cried.”
The islands, where wildlife evolved in isolation, have been particularly affected by human-caused extinctions introducing alien species into the ecosystem, and 11 of the species in the delisting proposal are from Hawaii and Guam. Pigs, goats, and deer destroy forest habitat. Rats, mongooses, and brown tree snakes feed on native birds and bats. Mosquitoes, which did not exist in Hawaii until they arrived on ships in the 19th century, kill birds by infecting them with avian malaria.
Hawaii was once home to more than 50 species of woodland birds known as honeycombs, some of them brightly colored with long, curved beaks that are used to drink nectar from flowers. Taking into account the proposed extinctions in this lot, only 17 species remain.
Most of the remaining species are now under increased siege. Birds that lived higher up in the mountains were once safe from avian malaria because it was too cold for mosquitoes. But due to climate change, mosquitoes have become more widespread.
“We are seeing a very dramatic population decline associated with that mosquito surge that is a direct result of climate change,” said Michelle Bogardus, deputy field supervisor for the Pacific Islands Office of Fish and Wildlife.
Only a couple of species have shown resistance to avian malaria, he said, so most are likely to face extinction unless mosquitoes can be controlled throughout the landscape.
Freshwater mussels are among the most threatened groups in North America, but scientists don’t know enough about the eight species on the list to say for sure why they disappeared. The extinctions are likely related to reservoirs humans built over the past 100 years, said federal biologists, who essentially turned mussel rivers into lakes.
Did the habitat change affect any aspect of your carefully choreographed life cycle? Were the filter feeders also damaged by sediment or contamination in the water?
Freshwater mussels are based on amazing adaptations developed over countless years of evolution. Females attract fish with an appendage that looks like a minnow, crayfish, snail, insect, or worm, depending on the species. The mussels then shed their larvae, which adhere to the fish, forcing it to take refuge and eventually distribute it.
Perhaps the mussels became extinct because their host fish moved or disappeared.
“I don’t think we fully understand what we lost,” said Tyler Hern, a Fish and Wildlife Service biologist whose work includes recovering freshwater mussels. “These mussels had secrets that we will never know.”