Yosemite Raptor Protection Program

Learn about the climbing closure process Yosemite biologists use to protect cliff -nesting raptors while maximizing climbing access.

Cliff Nesting Raptor Protection

The Yosemite Raptor Protection Program (YRPP) was established in 2009 to increase the reproductive success of cliff nesting raptors to raise young. This program focuses on surveying cliffs for nesting peregrine falcons and golden eagles. Both species are federally protected by the Migratory Bird Treaty Act, and golden eagles are protected under the Bald and Golden Eagle Protection Act. Since the program's inception, there have been 51 new peregrine nests documented throughout the park.

Why Climbing Closures?

Peregrine falcons and golden eagles are sensitive to disturbance during their breeding season, which is generally from March to August every year. Activities like climbing, slacklining, and even hiking can disturb nesting pairs, causing nest failure or abandonment of chicks. With the increasing popularity of recreational cliff activities in Yosemite, the YRPP implements a dynamic management strategy that uses adaptive closures instead of blanket closures.

Peregrine falcons are known for their aggressive and territorial behavior when they believe their nests are being threatened. Signs of aggressive behavior include bluff charging, frequent wailing, and very close fly-bys. If you notice that a raptor is agitated by your presence, the best action is to descend as quickly and safely as possible.

Adaptive Closures

Yosemite’s adaptive approach to climbing closures is unique among land management agencies. By observing the birds closely and studying individual pairs, park officials can establish smaller closure areas and fine-tune adjustments to the closure list throughout the season. Blanket closures often cover larger areas, that, because they are not actively monitored, stay closed for the entire breeding season.

Adaptive climbing closures seek to balance the need to protect these raptors with the park's founding principle of keeping the wilderness open and accessible to the public.

The Closure Process

Timeline of Closures

Climbing closures in Yosemite generally occur between March 1st and July 15th. In that time, park staff are busy surveying sites to determine where raptors are nesting so that closures can be adjusted accordingly.

March 1: Initial closures

Closures are reinstated at nest sites that have had confirmed active raptor nests within the last two years.

April-June: Closure Amendments

Closures are added and lifted as necessary to reflect updated nesting status. The official closure letters can be amended 1-6 times per season. It is critical for climbers to check for the most recently updated closures before going climbing.

July 15: Closures Lift

Most climbing closures are lifted after young have successfully fledged from their nests, usually by July 15. Some nests can have later fledging dates and can be extended past this date, so climbers continue checking closures into mid-August.

Current Closures

View a list of current climbing closures or a map of current climbing closures.

How Are Nesting Sites Found?

In Yosemite, peregrine falcon and golden eagle nest sites typically occur on sheer granite cliffs or domes below 10,000 ft. elevation and in proximity to a water source. There are 129 identified optimal cliff sites in the park. As of 2024, there are 20 known pair territories in the park: fifteen in Yosemite Valley, one in Hetch Hetchy, one in Lake Eleanor, two in Wawona, and one in the Grand Canyon of the Tuolumne. It is important to note that these closures reflect an intersect of nesting and climbing areas. The total number of territories in the park is likely much greater.

Survey Prioritization

Surveys are prioritized by:

1. Cliff sites with current climbing closures initiated on March 1.
2. Cliff sites in popular climbing areas.
3. Previously documented nest sites near climbing routes that do not have current climbing closures in effect (i.e., not active in the past two years).
4. Previously documented nest sites.
5. Areas without documented nesting, but with suitable habitat.

Park biologists follow up on climber and visitor reports of raptor sightings throughout the surveying season.

When Do Nestlings Leave the Nest?

According to the parks nesting chronology analyses from 2009-2024, 85% of peregrines fledged from the nest in the month of June, with 38% of those being in the week of June 11-20. A month buffer is given to young fledglings that still use the nest as they learn how to fly and to hunt.

2024 Breeding Season

The 2024 breeding season was successful for peregrines with 17 breeding pairs, 15 peregrine nests confirmed, and 23 young counted. The survey effort included 43 cliff sites, 63 historical nests, and 220 survey hours.

This brings the cumulative total of peregrine young from 2009-2024 to 385 individuals.

One golden eagle pair was monitored, protected, and successfully fledged one young.

Terminology

Raptor - a carnivorous (meat-eating) bird. All raptors share at least three main characteristics: keen eyesight, eight sharp talons, and a hooked beak. Another word for a raptor is "bird of prey".

Courtship - the behavior of birds and other animals aimed at attracting a mate

Eyrie/aerie - the nest of a bird of prey.

Fledglings - a young, fully feathered bird that has taken first flight from nest. Can also be called a juvenile.

Nestlings - a young bird developing in the nest that cannot fly.

Send a Report

If you want to report a sighting or have questions, please email us!