50 Years of Protecting Endangered Species

Kirtland's Warbler

Setophaga kirtlandii

In the birding world, a Kirtland’s warbler sighting is a big deal, and for good reason. The sparrow-size songbird has a very specific range and habitat: In the summer it nests on the ground only in young, dense jack pine forests in or adjacent to the state of Michigan. As the weather turns cold, the bird migrates to the Bahamas and nearby islands and over-winters in coastal scrub habitat. By the time the Endangered Species Act was signed in the 1970s, “there were less than 200 singing males,” says Patrick Doran, TNC’s associate state director in Michigan. The species faced two threats: the suppression of natural wildfires needed to maintain young tree growth, and predation by the brown-headed cowbird, which deposits its eggs in Kirtland’s warbler nests, creating a competitive environment in which the warbler chicks often lose. “They were getting hammered,” says Doran.

Through habitat management in the form of controlled burns and tree replanting, and through reducing the prevalence of brown-headed cowbirds, Kirtland’s warbler populations have risen dramatically. Delisted in 2019, current estimates suggest some 2,300 breeding pairs are alive today. Still, Doran says, the Kirtland’s warbler is reliant on continued conservation, and its fragility is perhaps what makes sightings so memorable.

Fender's Blue Butterfly

Icaricia icarioides fenderi

By 1937, biologists believed that this one-inch butterfly had gone extinct after losing much of its habitat in Oregon’s Willamette River Valley. “Nearly all native prairie [there] has been converted to agriculture, urban development and other land-cover types,” says TNC Willamette Basin Steward Jeff Rosier. In particular, the insect depends on Kincaid’s lupine, a wildflower upon which it lays its eggs. But in 1989, small populations of the butterfly were discovered, and in 2000 it was listed as endangered. Since then, numerous conservation efforts have allowed this tiny pollinator to rebound. Its range has doubled and known population sites have quadrupled, leading to its recent “downlisting” from endangered to threatened.

Topeka Shiner

Notropis topeka

This three-inch minnow “really speaks to the heartland of the U.S.,” says Steve Herrington, a TNC freshwater restoration strategy manager. Found in streams and creeks of the Great Plains, the shiner was listed in 1998 as endangered after centuries of agriculture-related development destroyed its habitat. Though the fish is still listed, ongoing land and water restoration projects have helped. One experimental program breeds shiners in a creek on Dunn Ranch Prairie—a TNC-owned preserve—and reintroduces them in nearby waterways. The collaboration with the U.S. Fish and Wildlife Service and the Missouri Department of Conservation has been so effective that the state is now testing new stream-restoration techniques.

Peregrine Falcon

Falco peregrinus

By the 1960s, peregrine falcons had vanished from the eastern part of the U.S. and had begun disappearing in the West. Their numbers dropped as a direct result of DDT, ingested through prey already carrying the pesticide. Like bald eagles, peregrine populations were devastated by a specific side effect of DDT that weakened eggshells, causing them to break prematurely under even normal amounts of pressure—like the weight of a parent’s body trying to keep them warm. Listed as endangered in 1973 under the Endangered Species Act, peregrines benefited first from the banning of DDT, and then from captive breeding programs led largely by The Peregrine Fund, a nonprofit founded in 1970 to protect its namesake from extinction. Now dedicated to conserving birds of prey worldwide, the organization no longer actively manages peregrines, says Chris McClure, Peregrine Fund’s executive vice president of science and conservation. “Peregrines are such a success story, we can take a step back and just watch from afar,” he says. The species was delisted in 1999 and now lives in almost every corner of the globe. One of the best places to spot one? Manhattan. “Peregrines need two things,” says McClure. “A cliff to breed on, and a bunch of prey.” With its abundant skyscrapers and pigeon populations, he says, “New York has both.”

Eggert’s Sunflower

Helianthus eggertii

This member of the Asteraceae family, known for its gold-hued blossoms and distinctive blue-green stems, can grow up to 7 feet tall. Eggert’s sunflower is native to Alabama, Kentucky and Tennessee. It was listed as threatened in 1997, when it could only be found in 14 counties scattered across those states. Preferring open, grassy areas and thickets, the plant was primarily threatened by habitat degradation in the form of commercial and residential development as well as land conversion for agriculture. But conservation efforts—including reduced use of herbicides and delayed mowing along roadsides where Eggert’s sunflower grows—have been so successful that, just eight years after being listed, it was delisted.