Peregrine Falcons of the Diablo Region
Peregrine falcons live year-round in the Mount Diablo region. Most active during the annual nesting season (February through July), these apex predators can often be spotted in Pine Canyon, where they have nested for millennia.
Photos by Wally De Young
The nesting areas in Pine Canyon and Knobcone Point are closed to visitors from February 1st through July 31st every year to protect the birds. View Closure Notice
Las áreas de anidación en Pine Canyon y Knobcone Point están cerradas a los visitantes desde el 1 de febrero hasta el 31 de julio todos los años para proteger a las aves.
Peregrine Team Update
2024-07-04
Thanks to abundant rains this past winter, Mount Diablo State Park was bursting with fresh plant life and consequently, plenty of small birds and mammals. These conditions encouraged successful nesting of some of our resident raptors such as red tailed hawks, red shouldered hawks, and prairie falcons. While the peregrines have maintained a consistent presence in the park, no nesting location has been identified yet and it appears we may not see any babies this year. Nevertheless, the area remains closed to all visitors (including the Peregrine Team) through the end of July.
MDSP is also home to one of the peregrine falcon’s natural enemies - the great horned owl (GHOW). The adults of each species rarely fight one another because the chance of injury is so high, but their nestlings, confined to their nests and unable to fly, are highly vulnerable. In Pine Canyon in 2021, all four peregrine chicks were killed by an adult GHOW just days before they flew from their nest for the very first time. This behavior is common in the wild, and it’s important to note that these babies were not eaten, but instead simply prevented from maturing into adults who could impart the same fate on owlets.
This season a GHOW nested in a cavity on one of the very rock faces used by the peregrines. This cavity however, had already been claimed by a pair of ravens. The great horned owl does not bother with such construction details, for they steal nests from other birds. The ravens were not pleased by this uninvited occupation, nor were the peregrines. At different times ravens relentlessly harassed the incubating owl and even removed some of the nesting material from the opening of the nest site hoping to evict the squatter. The peregrines also tried to intimidate the mother owl by flying past her nest cavity multiple times and sounding their alarm calls. It was quite a sight! The GHOW ultimately prevailed and our team members later saw her tending to an owlet. The ravens eventually moved on as well, choosing another fine cavity to raise their brood. And the peregrines continued their claim over the domain they call home.
About the Peregrines
Peregrine falcons are the fastest animals on earth and can dive at speeds over 200 mph while hunting small to medium-sized birds in mid-air. Because their survival depends on this speed, even a small injury can be deadly. Only 20% of peregrines make it through the first year of life.
Team Training Day - by Dereck Love
About the Peregrine Team
MDIA's Peregrine Team, a natural history education group, was formed in 2015 to assist park rangers during the nesting closure season. P-Team volunteers tell visitors about the peregrines, their habitat, and the importance of respecting the closure zone. P-Teamers also monitor the status of the falcons throughout the nesting season. Its members hail from a wide variety of backgrounds and include birders, hikers, runners, bikers, and equestrians, all of them nature lovers dedicated to preserving the area for future generations of people, peregrines, and the land we all depend upon.
For more information, contact: peregrine.team@mdia.org
Photo by Dereck Love
