Yosemite’s falcon boom

Yosemite’s peregrine falcons posted a record 2025 breeding season, with seven new nest sites and 23 fledglings documented on the park’s cliffs. (discoverwildlife.com) The new count follows a broader rise in the park’s falcon population. Yosemite counted 17 breeding pairs, 15 nests and 25 chicks in 2024, up from eight breeding pairs when its formal raptor protection program began in 2009. (smithsonianmag.com) (kmph.com) Park biologists say the rebound is tied to finding and monitoring more nest locations across Yosemite’s granite walls. The National Park Service says 51 new peregrine nests have been documented since the Yosemite Raptor Protection Program started in 2009. (nps.gov) A peregrine eyrie is simply a nest on a cliff ledge or other high perch. In Yosemite, those nests are often on sheer granite cliffs or domes below 10,000 feet and usually near water. (experience.arcgis.com) (nps.gov) The nesting boom has immediate effects for visitors because Yosemite closes specific cliff areas during breeding season. The park says climbing and slack-lining closures begin March 1 and usually last until chicks have fledged and dispersed, with amendments made through spring and early summer. (nps.gov 1) (nps.gov 2) Yosemite does not use blanket, park-wide shutdowns for these birds. Instead, biologists and climbing rangers adjust smaller closures around active nests, and Yosemite Conservancy says that approach keeps no more than 5% of climbing routes closed at one time. (nps.gov) (yosemite.org) That balance reflects how the species came back in the first place. Yosemite Conservancy says climbers helped recovery efforts in the 1990s by replacing DDT-thinned eggs with healthy, lab-hatched chicks, while the federal ban on DDT and other pesticides removed a major cause of the falcon’s collapse. (yosemite.org) (smithsonianmag.com) The species had vanished from Yosemite for decades before returning. The National Park Service says peregrine falcons were temporarily extirpated from much of their native range, including Yosemite, and Smithsonian reported the last known pair in the park before the comeback was seen in 1941. (nps.gov) (smithsonianmag.com) Yosemite’s cliffs are now being managed as both nesting habitat and recreation space, with daily monitoring continuing in 2026. The park and Yosemite Conservancy say the goal is to give peregrines enough room to raise young while keeping as much climbing access open as possible. (yosemite.org) (nps.gov)