Pinnacles Raptor Monitoring Program

Peregrine Falcon

Photo by Gavin Emmons

Pinnacles National Park has monitored cliff nesting raptors and the impacts of rock climbing on their nesting success since 1987. The park provides a diverse habitat for numerous cliff-nesting raptors, including California species of special concern such as prairie falcons (Falco mexicanus), peregrine falcons (Falco peregrinus), and golden eagles (Aquila chrysaetos), as well as a spectacular array of summits and cliff-wall routes for rock-climbers. Therefore, the behavioral and physical effect that climbers and off-trail hikers have on cliff-nesting raptors is studied.

In an average year, raptor monitors observe 11 pairs of prairie falcons, 2 pairs of peregrine falcons, 3 pairs of golden eagles, 6-10 pairs of American kestrels (Falco sparverius), 7 pairs of red-tailed hawks (Buteo jamaicensis), and 3 pairs of red-shouldered hawks (Buteo lineatus). Additional raptor species active and nesting in the park include Cooper’s hawks (Accipiter cooperii), sharp-shinned hawks (Accipiter striatus), and white-tailed kites (Elanus caeruleus). Owl species nesting in the park include long-eared owls (Asio otus), great-horned owls (Bubo virginianus), barn owls (Tyto alba), and western screech-owls (Otus kennicottii).

Raptor monitoring data is collected through the breeding season from January to July, and includes: nesting phenology, timing of breeding cycle, foraging ecology, reproductive behavior, reproductive success, and the impact rock climbing has upon these. To protect nesting birds of prey from human disturbance, raptor advisories and climbing/off-trail hiking closures go into effect every year during the raptor breeding season. Advisories and closures are posted in brochures at the Pinnacles Campground Visitor Center and West Side Visitor Contact Station, and on bulletin boards at the Eastside and Westside trailheads. By respecting the advisories and closures, visitors help to ensure the nesting success of the amazing birds of prey at Pinnacles National Park.