Peregrine Falcons Having Another Record Year at Pinnacles National Park

Adult female prairie falcon patrolling her territory. As of mid-May, the raptor monitoring team has confirmed nine prairie falcon pairs occupying territories within the park.

NPS / Gavin Emmons

May 2020 - The breeding raptor season is in full swing at Pinnacles National Park. Right now, prairie and peregrine falcon pairs are actively raising nestlings in cliff cavities throughout the park. Raptor advisories remain in effect to help keep the nestlings safe from disturbance. These advisories are informed each year by raptor monitoring efforts in the park. This year, the raptor monitoring team has been able to continue most of its work in spite of COVID-19. And as raptor monitoring seasons go, it has already been an exciting one!

As of mid-May, the raptor monitoring team has confirmed nine prairie falcon pairs occupying territories within the park. Of those, seven have nested, and team members have glimpsed a total of at least 17 nestlings. In addition, peregrine falcons set a new nesting record in the park for the second year in a row. Following several years of two nesting pairs in the park, the monitoring team recorded three nesting pairs last year. This year, they found four! These pairs are raising a total of at least eight nestlings, also a record. Peregrine falcons had been absent from Pinnacles for almost 50 years before they began returning to the park in 2004.

In years past, nesting peregrine falcons mostly seemed to push prairie falcon pairs out of their historical territories. More recently, the monitoring team noted that, at Balconies, the two species were tolerating each other nesting in close proximity. This year, they were pleasantly surprised to find a second instance of nearby nesting at South Chalone Peak. This suggests that, in certain locations, prairie and peregrine falcons can indeed tolerate each other and nest at the same time.

White-tailed kite pair copulating. A a white-tailed kite nest was a noteworthy find this year, as the habitat for this species, including the availability of California voles (their main prey), is somewhat marginal in the park.

NPS / Gavin Emmons

The monitoring team has found many other non-falcon raptor species nesting in Pinnacles this year as well. In all, they have confirmed 39 raptor nests for 11 species so far. One fun, noteworthy find was a white-tailed kite nest. The habitat for this species, including the availability of California voles (their main prey), is somewhat marginal in the park. The team also recorded a golden eagle nest, and multiple red-tailed hawk, red-shouldered hawk, Cooper’s hawk, American kestrel, great horned owl, barn owl, and long-eared owl nests. Since tree-nesting raptors like many of these are more likely to be found near park roads and facilities, such nesting records serve an important purpose. They offer park managers valuable guidance related to potential infrastructure projects and management plans near these facilities, and in other low-lying parts of the park.

For more information

• Pinnacles National Park Raptor Advisories
• Pinnacles National Park Raptors webpage
• San Francisco Bay Area Network Prairie and Peregrine Falcon Monitoring webpage
• Pacific Coast Science & Learning Center Prairie & Peregrine Falcons webpage
• Contact Gavin Emmons with any questions, or to report raptor observations in the park

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