Nesting peregrine falcons sign of species’ success

April 4, 2012

City dwellers got a taste of live-action wildlife on Friday, when three out of four peregrine falcon eggs hatched in San Francisco.

Perched in a nesting box high on a ledge of PG&E’s headquarters building in the financial district, the hatchlings are the newest members of the Bay Area’s steadily growing peregrine falcon population. A live streaming “nest cam” broadcasted the egg-hatching to a wide audience of followers who have been gaining interest in the nest and the overall fate of peregrine falcons in the area.

“The adventure begins,” said Cheryl Wolfcale-Elmore, an observer who has been watching the birds since 2005, when she realized the nest was set up across from her office building window. She is now part of an informal group of interested people that formed at the end stages of peregrine falcon recovery efforts to observe the birds in the city and the wild.


Photo by Malcolm NQ on Flickr

The group frequently gathers for a “fledge watch” when eggs are expected to hatch. “We sit from sunrise to sunset, carefully watching to make sure that they fledge okay,” Wolfcale-Elmore said. Typically, young birds must wait about 40 days before they are able to fly. “To have these birds in downtown San Francisco is really a wonderful thing because you don’t expect that kind of bird to be coexisting with us in the city.”

A phenomenal success story

The hatchlings are contributing another chapter to the species’ phenomenal success story in the region, said Glen Stewart, director of the UC Santa Cruz Predatory Bird Research Group. The group revived the peregrine falcon population after the species was nearly decimated forty years ago from the effects of the pesticide DDT. Even though the chemical was banned in the 1970s, it had long-lasting and devastating effects on peregrine reproduction and growth.

When only two known mating pairs were left in the wild, Stewart and his team began breeding the birds in captivity. “Peregrines had never been bred on a large scale, and most people thought that it couldn’t be done,” he explained. The group’s efforts paid off in 1999, when the birds were taken off the endangered species list. Now there are an estimated 35 mating pairs in the Bay Area and 250 pairs statewide.

Favored by falconers, peregrines are skilled hunters that prey on other birds mid-flight. When swooping down to capture birds, they can reach speeds of up to 200 mhp, making them the fastest members of the animal kingdom. While peregrines can be found in almost any environment, they thrive in coastal areas.

Cities are also ideal locations for peregrine falcons because they prefer to nest on structures that dominate the landscape, such as skyscrapers and bridges. In addition, cities provide the birds with a large source of food because pigeons are the perfect size meal for the predator.

“People admire peregrines because they’re totem animals,” Stewart said. “They are the fastest animal on the planet and have super hero abilities.”

Conserving a species

By going on nature walks to spot peregrines, observers such as Wolfcale-Elmore are helping contribute to ongoing conservation efforts. “I’m able to do some science by taking phone calls and emails at my desk from people that have turned into experts observers,” Stewart said.

Being able to watch birds nested in the city has been the biggest contributor to conservation efforts and awareness. “It’s a great success story and it’s particularly important because people can look out their window and see a real symbol of the wild,” Stewart said.

Three other nests are set up in the Bay Area, including one with a web camera on the City Hall building in San Jose, and two undisclosed locations in Hayward and Oakland. At all four sites, invading peregrines have attempted to take over inhabited nests, a healthy sign for the species, according to Stewart. “That means there are more peregrines than there are places for them to nest,” he explained. “I don’t think this has occurred in the Bay Area since 1945 — or maybe ever.”

The result will be a fight for survival of the fittest. Otherwise, if the birds cannot find a nesting spot in the city they’ll likely retreat to the wild, Stewart said.

For some San Francisco residents, the birds are welcomed neighbors and the more that come, the better. “Having peregrine falcons in the city has opened my eyes and a lot of other people’s eyes to the nature out there,” Wolfcale-Elmore said.

Watch the nesting peregrine falcons.

About the Author

Renee Frojo is a Bay Nature contributor.

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