Blog Post Jennifer Errick Nov 2, 2015

9 Wildlife Success Stories

National parks provide critical habitat for a variety of animals—in some cases, they are the only places that threatened or endangered species have left to call home.

Here are nine species that are making a comeback thanks in part to the role of national parks and other public lands.


1. Pacific fishers

Mount Rainier, North Cascades, and Olympic National Parks, Washington

Pacific fishers once roamed the forests of the northwestern United States, building dens and raising kits among the old-growth trees of the Cascade Mountains. Now, after decades of trapping and logging, the animals are all but gone from Washington state. In 2008, the National Park Service, the Washington Department of Fish and Wildlife, and the U.S. Geological Survey began reintroducing fishers to Olympic National Park, which contains some of the state’s best remaining habitat. The program was so successful, officials expanded the program to Mount Rainier and North Cascades National Parks in 2013. Sometimes referred to as “fisher cats,” these animals look feline, but are more closely related to otters. And they don’t eat fish, as far as people have observed, though they are deft hunters that feed on a number of land animals and plants—and one of the few predators that routinely take down porcupines.


2. Black-footed ferrets

Badlands and Wind Cave National Parks, South Dakota

These two-foot-long members of the weasel family were once considered the rarest mammals in the world. The ferrets depend on prairie dogs as their primary food source, and the human extermination of prairie dog populations in some parts of the country nearly wiped out the ferret, which was officially recognized by the government as threatened in 1967 and listed as endangered after the Endangered Species Act became law in 1973. By 1987, only 18 were known to be left in existence. These 18 animals were put into a captive breeding program, and the Park Service began reintroducing the ferrets to Badlands National Park in 1994 and Wind Cave National Park in 2007. The animals have also been reintroduced to other locations in Wyoming, Arizona, Montana, Utah, Colorado, Kansas, and Chihuahua, Mexico. Thanks to decades of work involving multiple government agencies, about a thousand of these ferrets now live in the wild.


3. Gray wolves

Yellowstone National Park, Idaho, Montana, and Wyoming

Gray wolves were methodically eradicated from Yellowstone National Park and the surrounding area by the mid-1920s due to government-sanctioned programs meant to protect livestock. Over time, however, researchers began to understand the critical role predators like wolves play in maintaining a healthy ecosystem. After consulting with wildlife experts, considering public comments, and creating a solid strategy, the U.S. Fish and Wildlife Service worked in cooperation with the Park Service to release gray wolves into Yellowstone National Park in the mid-1990s. That effort is now hailed as a success not just for the wolves but also for the long-term health of the park and its many other inhabitants. About 100 gray wolves now live in the park, where visitors clamor to see them and scientists continue to study them.


4. Bald eagles

Channel Islands National Park, California

Bald eagles once nested on each of the five islands in this national park, but by the 1950s, the birds had disappeared, largely due to exposure to DDT—a synthetic pesticide famously exposed as an environmental danger in Rachel Carson’s Silent Spring. The Montrose Settlements Restoration Program provided funding to reestablish bald eagles in the Channel Islands in 2002. Biologists brought in eaglets from Alaska and breeding programs in other parts of the country, and released 61 eagles between 2002 and 2006. Now more than 40 live at the park, including about a dozen breeding pairs; January through June is the best time to see them.


5. Desert pupfish

Organ Pipe Cactus National Monument, Arizona

This shiny minnow-like creature may look like just another small aquatic species, but it is one of the most extreme survivors of any animal on Earth. The pupfish can withstand severely cold and hot water, water that is three times saltier than the ocean, and even highly acidic water. Despite all this, groundwater pumping dried up much of the pupfish’s habitat, and competition from non-native species contributed to the fish’s decline; it has been on the Endangered Species List since 1986. One particular spring and pond in Organ Pipe National Monument serves as an ideal habitat for these small, spectacular fish, but invasive animals introduced to the park became a threat. In response, park staff drained the pond, removed the invasives, and “reintroduced” the pupfish back into its native environment. Today, an estimated 4,000 to 5,000 pupfish live and thrive in the park’s Quitobaquito Springs.


6. Bighorn sheep

John Day Fossil Beds National Monument, Oregon

Bighorn sheep once thrived in the John Day River Valley in Oregon, but overhunting and diseases from domesticated sheep led to their demise—the last known sheep in the area died around 1905. After 12 years of collaboration among the National Park Service, the Oregon Department of Fish and Wildlife, the Bureau of Land Management, ranchers, and others, officials transported 20 bighorn sheep more than 100 miles by truck and released them near the national monument and adjacent lands in 2010. These icons of the American West once dotted the cliffs and hillsides of the area; now visitors have a chance to see them again as the animals begin to repopulate their historic range.


7. California condors

Pinnacles National Park, California

California condors once ranged throughout the skies of western North America, but by 1982, fewer than 22 remained. A variety of human activities led to the population decline, including the use of lead ammunition, which poisons the animals the condors feed on. Now the birds are making a comeback thanks to reintroduction efforts the U.S. Fish and Wildlife Service initiated in 1985 at what is now Pinnacles National Park. These efforts have boosted the bird’s numbers to about 210 in the wild and 180 in captivity.


8. Elk

Great Smoky Mountains National Park, North Carolina and Tennessee

Elk had long roamed the Great Smoky Mountains before hunting, trapping, and habitat loss wiped them out by the mid-1800s, well before the area became a national park in 1934. By the early 1900s, elk populations had declined so significantly across the country, conservationists feared the animal was headed for extinction. The Park Service began reintroducing the species to the area in 2001. Now about 140 elk live in the park and surrounding area, with new calves born each year.


9. Nēnē

Hawai'i Volcanoes National Park, Hawaii

Nine species of native goose evolved on the Hawaiian Islands, but the nēnē is the last type that still exists there. Thousands of nēnēs once thrived on the archipelago, but hunting, habitat loss, and invasive predators like mongooses, cats, and dogs brought the nēnē population as low as 50 by the 1940s. Park officials have been helping to restore healthy populations since the 1970s through captive breeding and reintroduction programs, and their numbers have grown significantly, though predators and human interference continue to threaten these birds. Park biologists carefully monitor their movements and maintain safe spaces for nēnēs to nest and brood.

About the author

  • Jennifer Errick Managing Editor of Online Communications

    Jennifer co-produces NPCA's podcast, The Secret Lives of Parks, and writes and edits a wide variety of online content. She has won multiple awards for her audio storytelling.

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