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.
Please note the nesting cliffs in Pine Canyon are closed to visitors from February 1st through July 31st every year to protect the birds.
About the Peregrines
Peregrine falcons are the fastest animals on earth, able to dive at speeds of over 200 mph while hunting small to medium-sized birds, their typical prey. Because their survival depends upon such high speeds, even a small injury can be deadly. Only 20% of peregrines make it through the first year of life.
The birds flourished in the early 20th century prior to the development of the pesticide DDT.
On the Brink of Extinction
After World War II, extensive use of DDT nearly wiped out peregrines and several other bird species. Because it interfered with calcium production, the eggs could not withstand even the weight of an incubating parent. The shells cracked or collapsed, and the embryos died. As a result, by 1950, peregrines had disappeared from Mount Diablo. By 1970, only two nesting pairs could be found in all of California. By 1975, peregrine numbers had dropped 80-90% nationally.
DDT was finally banned in 1972. Conservation groups, businesses, biologists, and dedicated volunteers came together locally and nationally to launch recovery projects, which were successful beyond all expectations. Peregrine falcons can now be found in almost all their old haunts, including Pine Canyon.
Today there are about 350 nesting pairs in California and 4,000 nationally.
Today’s Threats to Falcons
In 1999, peregrine populations had recovered enough to be removed from the Endangered Species List. Although the threat of DDT has waned, the steep increase in visitors to our parks poses another threat to the birds. Peregrines and humans both like cliffs; however, peregrines are highly territorial during their nesting season, and if disturbed, they may become too distracted to pay proper attention to their eggs and young. On occasion, parents abandon nests altogether. In response, Mount Diablo State Park closes the Pine Canyon cliffs annually during the nesting season, from February 1st through July 31st.
About the Peregrine Team
The Peregrine Team in Pine Canyon (P-Team), a natural history education group, was formed in 2015 to assist park rangers during the nesting closure season. P-Team volunteers engage with visitors to the park about the peregrines, their habitat, and the importance of respecting the closure zone. Members also monitor the status of the falcons throughout the nesting season. P-Teamers hail from a wide variety of backgrounds and include birders, hikers, runners, bikers, all of them nature lovers dedicated to preserving the area for future generations of people and peregrines.
For more information, contact Staci Hobbet, Peregrine Team Lead, email@example.com.
Peregrine in flight - Scott Hein
3 Falcons in cavity - Kendall Oei
Team Training Day - Dereck Love