Peregrine falcons are making a remarkable comeback in Yosemite National Park, thanks in part to the collaborative efforts of rock climbers and conservationists.

Once declared federally endangered in 1970 and added to California's endangered species list in 1971, these birds faced drastic population declines due to pesticide use.

The use of DDT after World War II led to thin eggshells and a significant drop in peregrine falcon populations, which dwindled to just 324 pairs in the U.S. by 1974.

The ban on harmful pesticides like DDT in the early 1970s facilitated the falcons' recovery, allowing their population to rebound to an estimated 40,000 individuals in North America by the late 1990s.

In 1978, climbers discovered an active peregrine nest on El Capitan, prompting significant conservation efforts, including the incubation of eggs in laboratories.

Thanks to a 15-year recovery plan, the number of breeding pairs in Yosemite has increased from eight in 2009 to 17 pairs in 2024.

Since 2009, a total of 51 nesting sites have been documented in Yosemite, producing 385 baby peregrine falcons, showcasing the success of ongoing conservation efforts.

Climbers have played a crucial role in this recovery by reporting active nests and assisting in the collection and incubation of eggs, successfully returning over 1,000 young peregrines to the wild.

The peregrine falcon was completely absent from Yosemite after 1941 but has since been designated as a 'fully protected' species in California.

The National Park Service has implemented climbing route closures to protect nesting sites, affecting less than 5% of the park's climbing routes, allowing climbers to continue their activities largely unaffected.

Ken Yager, one of the climbers involved in the initial rescue efforts, expressed pride in the successful conservation of peregrine falcons, emphasizing that without these efforts, the birds might have disappeared from Yosemite.

The park service has reported a 'remarkable comeback' of peregrine falcons since the 1970s, when there were no nesting pairs in Yosemite.