Center for Biological Diversity

For Immediate Release, June 21, 2016

Contact: Loyal Mehrhoff, (808) 351-3200,

Analysis: 85 Percent of Continental U.S. Birds Protected by Endangered Species Act
Have Increased or Stabilized Since Being Protected

Recovering Birds Include Interior Least Tern, Northern Great Plains Piping Plover, Bald Eagle

WASHINGTON— Eighty-five percent of continental United States birds protected under the Endangered Species Act increased or stabilized their population size since being protected, according to a new report by the Center for Biological Diversity. The average population increase was 624 percent. 

Average Recovery of Birds
Interior least tern
Interior least tern courtesy USFWS. Photos are available for media use.

A Wild Success: A Systematic Review of Bird Recovery Under the Endangered Species Act is the first-ever study to examine the year-by-year population size of all 120 bird species protected under the Endangered Species Act. Drawing on more than 1,800 scientific population surveys, the analysis concludes that the Act has recovered imperiled birds at the rate and magnitude intended by its congressional creators and administrative overseers.

Among the endangered birds improving in Idaho, Montana and Wyoming are the interior least tern (up 603 percent since 1985) and the northern Great Plains piping plover (up 180 percent since 1986).

“Birds like the northern Great Plains piping plover were in big trouble before they were protected under the Endangered Species Act,” said Loyal Mehrhoff, the Center’s endangered species recovery director. “But the recovery tools provided by the Act have helped us pull dozens of species back from the brink of extinction.”

Key findings of the report:

  • 85 percent of continental U.S. birds increased their population size or stabilized since being protected under the Endangered Species Act.
  • The average population increase was 624 percent.
  • 61 percent of Pacific Island (Hawaii, Guam, Palau and the Commonwealth of the Northern Marianna Islands) birds have increased their population size or stabilized since being protected under the Endangered Species Act. The weaker performance is due to lower funding levels, smaller population sizes at the time of Endangered Species Act listing, and more species being threatened by difficult to manage invasive predators and diseases.
  • Few birds were expected to recover by 2015 because they have been protected under the Act for just 36 years on average, while their federal recovery plans estimate 63 years is needed.
  • Birds are recovering at the rate expected by federal recovery plans.
  • Endangered birds fared much better than unprotected birds, which on average declined 24 percent since 1974. This is because endangered birds are being actively managed, while common birds generally are not.

Among the Northern Rockies birds in today’s report:

Interior least tern — Before being protected as endangered in 1985, the smallest of the North American terns, which prefers nesting on sandbars along major rivers like the Missouri and Mississippi, had seen its numbers plummet below 2,000 birds due to the spread of invasive plants and unnatural changes to river flows caused by dams. Endangered Species Act protections helped its population increase to nearly 14,000 by 2012.

Northern Great Plains piping plover — The populations of this energetic shorebird plummeted in the 20th century due to increased development and recreational uses of shorelines, with even relatively remote nesting sites on inland lakes damaged by dams and other intrusive water-control practices. Protected as endangered in 1985, its populations rebounded from only 525 breeding pairs in 1986 to nearly 1,500 by 2008.

Bald eagle — By the time the national bird was protected as endangered in 1967, hunting, feather collecting and DDT had virtually eliminated it from many states. But with DDT banned and federal protections in place, the population soared from a total of only a couple dozen nesting pairs in Montana, Wyoming and Idaho in the 1970s to more than 600 by 2006-2007. By the time the species was delisted in 2007, the number of bald eagle pairs in the lower 48 had increased from just 416 in 1963 to more than 11,000.

Read more in the report and about other Endangered Species Act successes here.

The Center for Biological Diversity is a national, nonprofit conservation organization with more than 1 million members and online activists dedicated to the protection of endangered species and wild places.

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