Close Call: The Near-Extinction of Peregrine Falcons
Falco peregrinus
by Anastasia Hobbet
Dave Furseth
The fastest animal on earth is a neighbor of yours. It’s the peregrine falcon, clocked at well over 200 miles per hour during its precipitous dives while hunting. Address? Mount Diablo State Park and surroundings, where at least two pairs are now readying themselves to nest in the dramatic pinnacles of Pine Canyon and the remote Black Hills above Black Hawk, where they will spend the spring and summer brooding the eggs and nurturing the youngsters until the kids become independent. Sounds rosy, but there’s a big “if" needed at this point: if the birds can get enough privacy and seclusion. They need a lot of quiet space, and with well more than 100,000 visitors per year now visiting Pine Canyon, is privacy possible for any creature?
The responsibility for ensuring some seclusion for the Pine Canyon birds falls to two parks: Castle Rock, which is an East Bay Regional Park; and Mount Diablo State Park. The main access to lower Pine Canyon is via the former, but Pine Canyon's sandstone cliffs lie just over the boundary inside the State Park, forming a section of its westernmost edge. Two annual nesting closure zones stretching from Februrary 1 through July 31 help these blistering-fast aerial hunters feel some confidence in their security. The staffs of the two adjacent parks cooperate in enforcing the closure, but it's tough for a park supervisor working with a tiny staff to dispatch anyone fast, which is key.
Widespread use of DDT beginning in the late 1950's almost wiped out peregrines in the U.S. and across the western world. It interfered with calcium deposition, thinning the mother's eggshells so much that they cracked when she tried to sit on them. The embryos died, pitching the population into collapse. DDT was finally banned in the U.S. in 1972, and some years later, Save Mount Diablo inspired a massive, successful effort to return the birds to Castle Rock. Keeping the birds safe during their six-month breeding has proved dicey. The Covid era drove cabin-fevered people into the parks -- all parks everywhere -- and even the most secluded places on and around Mount Diablo, on legal trails and hacked trails, became patterned with boot prints, bike tires, and horse hooves.
MDIA volunteers formed the Peregrine Team in 2015 to support the closure zone enforcements of the rangers and staff in the two parks. This (2024) is the team's 10th season. In addition to informing hikers about the closure, they spot hikers in the closure area, and, if possible, gently interact with them when they return to the legal trail -- or even better: before they leave it -- about the ethics and benefits of respecting closure zones.
You can help too. Plan to hike Stage Road in Pine Canyon and the trails from Curry Point. You'll see closure signage. Visit with other hikers as you go. If you spot people who may be headed into the closure zones, draw their attention gently to the signs. If they choose to trespass, don't intervene. They'll remember your words. Crowd-sourcing works -- eventually.