23 Species Declared Extinct by U.S. Government as Scientists Warn of 'Extinction Crisis'

Officials announced Wednesday that 23 birds, fish and other species are now extinct in the U.S., a blow to the country's eco-diversity.

Declaring an animal extinct is a last resort for wildlife officials, but scientists with the U.S. government say there is no sign of the nearly two dozen now filed under extinct. They added that climate change and environmental pressures could mean more extinctions as the plant warms, threatening fragile plants and animal populations.

"When I see one of those really rare ones, it's always in the back of my mind that I might be the last one to see this animal again," said Anthony "Andy" Ford, a U.S. Fish and Wildlife Service biologist in Tennessee who specializes in freshwater mussels.

For more reporting from the Associated Press, see below.

The ivory-billed woodpecker was perhaps the best known species the U.S. Fish and Wildlife Service declared extinct. The woodpecker went out stubbornly and with fanfare, making unconfirmed appearances in recent decades that ignited a frenzy of ultimately fruitless searches in the swamps of Arkansas, Louisiana, Mississippi and Florida.

Others such as the flat pigtoe, a freshwater mussel in the southeastern U.S., were identified in the wild only a few times and never seen again, meaning by the time they got a name they were fading from existence.

"Little is gained and much is lost" with an extinction declaration, said Cornell University bird biologist John Fitzpatrick, lead author of a 2005 study that claimed the woodpecker had been rediscovered in eastern Arkansas.

"A bird this iconic, and this representative of the major old-growth forests of the Southeast, keeping it on the list of endangered species keeps attention on it, keeps states thinking about managing habitat on the off chance it still exists," he said.

The International Union for Conservation of Nature, a Switzerland-based group that tracks extinctions globally, is not putting the ivory-billed woodpecker into its extinction column because it's possible the birds still exist in Cuba, said the group's Craig Hilton-Taylor.

Hilton-Taylor said there can be unintended but damaging consequences if extinction is declared prematurely. "Suddenly the [conservation] money is no longer there, and then suddenly you do drive it to extinction because you stop investing in it," he said.

But wildlife officials said in an analysis released Wednesday that that there have been no definitive sightings of the woodpecker since 1944 and "there is no objective evidence" of its continued existence.

They said the 23 extinction declarations were driven by a desire to clear a backlog of recommended status changes for species that had not been acted upon for years. They said it would free up resources for on-the-ground conservation efforts for species that still have a chance for recovery.

What's lost when those efforts fail are creatures often uniquely adapted to their environments. Freshwater mussel species like the ones the government says have gone extinct reproduce by attracting fish with a lure-like appendage, then sending out a cloud of larvae that attach to gills of fish until they've grown enough to drop off and live on their own.

The odds are slim against any freshwater mussel surviving into adulthood—a one in a million chance, according to Ford—but those that do can live a century or longer.

Hawaii has the most species on the list—eight woodland birds and one plant. That's in part because the islands have so many plants and animals that many have extremely small ranges and can blink out quickly.

The most recent to go extinct was the teeny po'ouli, a type of bird known as a honeycreeper discovered in 1973.

By the late 1990s just three remained—a male and two females. After failures to mate them in the wild, the male was captured for potential breeding and died in 2004. The two females were never seen again.

The fate of Hawaii's birds helped push Duke University extinction expert Stuart Pimm into his field. Despite the grim nature of the government's proposal to move more species into the extinct column, Pimm said the toll would probably have been much higher without the Endangered Species Act.

Since 1975, 54 species have left the endangered list after recovering, including the bald eagle, brown pelican and most humpback whales.

Climate change is making species recovery harder, bringing drought, floods, wildfires and temperature swings that compound the threats species already faced.

How they are saved also is changing. No longer is the focus on individual species, let alone individual birds. Officials say the broader goal now is to preserve their habitat, which boosts species of all types that live there.