FAQs About Peregrines

Are Peregrines really the fastest animals on earth?

Yes, Peregrine falcons are able to vertically dive or "stoop" at up to 200 mph, but only while hunting. However, a peregrine will always be faster when compared with other birds. In non-hunting mode, a peregrine flies at 25 to 34 mph. And when both peregrine and prey are near the ground, the falcon's direct pursuit reaches speeds around 70 mph. It is when the peregrine flies high and spots a meal down low that it can shift to its electrifying vertical speeds.

What happens if someone trespasses a closure zone during nesting season?

Trespassers can be warned, cited, and/or criminally prosecuted for entering a closure zone during nesting season. MDSP Posted Order No. 011-21-680-203, effective July 1, 2021, closes two rock formation areas in MDSP to “all pedestrian, equine, bicycle, or any other mode of public transportation or public usage, annually from February 1, through July 31.” To view the closure notice, go to: https://www.parks.ca.gov/?page_id=517

How long have Peregrine falcons nested in Mount Diablo State Park?

Mount Diablo is an ancestral home of peregrines. Peregrine falcons belong here on Mount Diablo, where they have nested for millennia, where they have an abundance of food, high natural cliffs, and rich hunting grounds. We humans are the visitors, not the peregrines. As stewards of this land, we have the responsibility to protect these iconic raptors.

Have the number of peregrines in California recovered?

Yes, but human visitors are even more capable of going everywhere, fragmenting the habitats for plants and animals. Peregrines need peace and privacy to feel confident about spending six months of their short lives every year to raise their chicks.

Are there other threats to the peregrine falcon population besides us humans?

A recent global outbreak of bird flu continues to kill birds, both wild and domestic. Because peregrines hunt pigeons, shorebirds, ducks, grebes, gulls, and songbirds, peregrines are at risk for infection from exposure through their diet. Peregrines can also contract lead poisoning and pesticide contamination by eating infected prey. Additionally, new poisonous chemicals show up regularly on our store shelves and their potential risks to wildlife, including peregrines, is unknown. Even DDT isn't completely gone, though it was banned in the United States in 1972. Environmental researchers have recently tracked down a million and a half barrels of DDT dumped for decades near Catalina Island during the last century.

Why is the nesting area closed to the public for 6 months?

It takes time to raise kids from scratch, and anything can go wrong. For peregrines, close human proximity can be one of those things, drawing their attention from their core job of hunting and caring for their chicks. Human disturbances in the territory, especially while the chicks are in the nest, may cause the parents to abandon the nest, leaving the youngsters to starve to death or become a meal for another predator. See the full timeline at: https://www.mdia.org/peregrine-timeline

What is the average wingspan of a peregrine falcon?

The average wingspan of a peregrine falcon is around 3 feet.

What do peregrine falcons eat?

Peregrine falcons primarily feed on other birds, such as pigeons and ducks.

Where do peregrine falcons nest?

Peregrine falcons typically nest on high cliffs or tall man-made structures, such as skyscrapers. Urban nests are at risk to human disturbance or excessive human intervention. For this reason, it is important to preserve and protect natural nesting areas.

How many eggs does a peregrine falcon lay in a clutch?

Peregrine falcons usually lay 3 to 4 eggs in a clutch.

What is the typical survival rate of peregrine chicks?

Peregrine chicks only have a 10-20% survival rate, once on their own. This makes protecting the nesting areas for a short time each year even more important to ensure their survival.

Where can someone safely observe the falcons?

Diablo Foothills Regional Park, 1700 Castle Rock Road, in Walnut Creek: https://www.ebparks.org/parks/diablo-foothills
Starting at the Park entrance, walk through the park’s recreation area and hike on Stage Road past the intersections of Fairy Lantern Trail and Buckeye Ravine Trail, for approximately 1 mile. You’ll find yourself in the first of two large meadows on your right.  Look for the interpretive sign uphill to your right and view the Castle Rock cliffs from there. Depending on the raptor activity, you may also want to cross the creek and watch the birds from the second meadow across from the rock formations. The round trip hike from the Diablo Foothills Regional Park parking area to the second meadow and return is approximately 2.6 miles. In Spring, you may encounter water crossings along the trail.

How does the vision of peregrine falcons compare with humans?

Unquestionably, a peregrine’s eyesight is extraordinary and is 8 times better than human vision. Peregrines can spot small prey from 1 to 2 miles away. Imagine being able to spot a rabbit 15 football fields away! Peregrines also have “fast vision.” Consider an animal’s visual flicker fusion rate, in other words, its ability to track rapidly changing visual events. Peregrines can see 129 images per second compared to a human’s 25 images per second. Peregrines also have approximately a million retinal cones allowing them to see color variation in the ultraviolet range, compared to our mere 30,000. By any measure, peregrines have far better vision than humans.

Where besides North America, do peregrine falcons live?

Peregrines live on every continent except Antarctica.

What does history tell us about the relationship between humans and peregrine falcons?

The falcon was considered king of the birds in ancient Egypt and was associated with several gods, including the sky god Horus, who was often shown with the head of a falcon. Humans and peregrines have a long relationship in the practice of falconry. Although historians disagree about when falconry began, records establish that an Iranian king, who may have lived as long as 10,000 years ago, used birds of prey to hunt. By 2000 BC, falconry was well-established in the Middle East and eventually migrated throughout Europe. Modern falconers still favor peregrines.