Peregrine Falcon Chicks Born On PG&E Headquarters Now Have Tracking Bands

Bob Butler
April 14, 2019 - 8:58 am
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SAN FRANCISCO — Three peregrine falcon chicks born three weeks ago have been fitted with new identification bands. It is the latest in a success story for the formerly endangered species that has played out over the past five decades.

The chicks are nesting on the roof of PG&E's headquarters, with sweeping views of the Bay Bridge and the bay. It is apparently a perfect spot for their parents to spot prey. 

In the 1970s there were only two breeding pairs of the birds in California. Thanks to captive breeding programs like the one at the UC-Santa Cruz Predatory Bird Research Group, there are now 300 breeding pairs in California.

“That and the banning of the pesticide DDT that was resulting in eggshell thinning and breakage which was the reason for the low population numbers,” said research group director Dr. Keva  Glucs. “Those two things together ended up recovering this endangered species. And it‘s one of the few species that has been taken off the endangered species list.”

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A small delegation, accompanied Dr. Glucs, recently went to the nest to place identification bands on the three male chicks, which were rather sleepy after having apparently just eaten. The intrusion awoke the chicks and sent their parents flying angrily around. 

“The only way that we can tell where these birds are going, how long they’re living, how successful they are in the wild is by keeping track of individuals,” Glucs said. ‘These bands allow us to know that we’re seeing the same birds year after year in a certain location.”

Falcons used to nest under the Bay Bridge but moved to the top of the PG&E skyscraper to prey on rock pigeons.

“Those are perfect prey for the peregrine falcon," said Glucs. "They can catch them in flight and they’re numerous, so these birds are not running low on food at any time during the year.”

Glucs said it doesn’t hurt that pigeons are drawn to Giants games at Oracle Park and the crowds at Union Square and Pier 39.

There are now 40 breeding pairs of peregrine falcons in the Bay Area. 

Researchers believe the three young males will take their first flight by the end of the month.