A Record Falcon Season at Pinnacles National Park, 2022

An adult female prairie falcon at her nest cavity, with three nestlings about 25–27 days old; prairie falcons fledge at about 42 days. Photo by Gavin Emmons, National Park Service.

When the 2022 raptor monitoring season began at Pinnacles National Park, it seemed unlikely the park's falcons could top the year before, when they raised 40 young. They did. By July, wildlife biologist Gavin Emmons of the San Francisco Bay Area Network's falcon monitoring program reported:

• Nine prairie falcon pairs and four peregrine falcon pairs nested, and every pair fledged young — 46 in all.
• That is the most falcon fledglings in a season since monitoring began, matched only once before, in 2013.
• It was the first season with no failed nests since 2005.
• The peregrines alone fledged 14 young, a record for the program's 35 years.

Why so successful?

With so many variables, no one is sure why nesting went so well two years running. Prairie falcons, at least, may have gained from low rainfall in December and January, which meant sparser vegetation hiding their main prey — ground squirrels, other rodents, and grassland birds such as meadowlarks.

Prairie falcon young at the nest cavity a few days before fledging, amid the lichens and breccia of the park's cliffs. Photo by Gavin Emmons, National Park Service.

Other raptors

The team also confirmed 24 nests of other birds of prey in the park: American kestrels, red-tailed and red-shouldered hawks, Cooper's hawks, and great horned, western screech and long-eared owls. Mike Baird, Kaitlin Lopez, Joseph Belli and Megan Gnekow, longtime members of the park's condor and raptor monitoring programs, helped confirm nesting throughout the season.

Advisories

Raptor advisories, which protect nesting birds of prey from disturbance, were lifted for the rest of 2022 except at Little Pinnacles / Yaks. Climbers and off-trail hikers respected them well. More is on the park's raptors page and the network's falcon monitoring page.

Sources

• National Park Service, Bay Area Nature & Science Blog: "2022 a Second Amazing Year in a Row for Nesting Falcons at Pinnacles National Park," by Gavin Emmons (July 2022).