Peregrine falcons are the fastest animals on earth, capable of diving at upwards of 200 miles per hour to capture smaller birds, their main prey. It’s quite a sight to see a peregrine dive, especially in light of the decline in peregrine populations when the pesticide DDT was used widely in the US. The checmical was banned in 1972, but not before the bird disappeared across large parts of the country. In California in 1970, only two nesting pairs could be found in the whole state.

Peregrines have recovered slowly but steadily—California now has about 350 nesting pairs. Their restoration, including locally, was accomplished over many years by the efforts of bold biologists and determined volunteers. Now the falcons nest every year on Mount Diablo, sometimes successfully, sometimes not.

Peregrines are highly territorial and need some privacy to nest successfully. If they feel insecure due to a lot of human traffic near their nest, they may become too distracted to lay eggs, incubate, or feed their young, and sometimes they abandon the nest altogether.

To help them gain some privacy, the cliffs along the western edge of Mount Diablo State Park are closed to all park users annually from February 1st to July 31st. But with nearly 100,000 visitors per year using these public lands, many hikers still scale the rocks. Most don’t know about the falcons so be sure to acknowledge the signage indicating when these special birds need their space.