Four peregrine falcon chicks that hatched in early April atop the PG&E headquarters at 77 Beale St. in San Francisco were banded on Monday by researchers.

Zeka Glucs, director of the University of California, Santa Cruz Predatory Bird Research Group, checked the health and weights of the birds, determined their genders and applied the bands. Once the birds leave the nest, and perhaps downtown San Francisco, bird watchers will be able to see the birds’ band numbers and share their location.

The birds will begin learning to fly in the next three weeks.

Although their new leg bands have numbers and letters for identification, PG&E is asking customers to help name the baby birds — two females and two males.

Customers can submit names using the hashtag #pgefalcons on Twitter and Instagram, or by emailing This email address is being protected from spambots. You need JavaScript enabled to view it.. The deadline is Friday, May 7.

Names will be chosen from the submissions and announced next week. Past winning names have been inspired by Golden State Warriors players, movie characters and even the namesake of an elementary school in Watsonville.

Bird lovers across the world tune in each spring via PG&E’s live, high-definition webcam to watch the peregrines raise a new clutch of young. In April alone, the webcam posted roughly 1.7 million views.

“In addition to 77 Beale’s importance as an indicator of species recovery, this nest has provided deep connection with the peregrine-recovery story for people around the world,” Glucs said. “This nest and its webcam are the No. 1 personal peregrine encounter I hear about when I tell people what I do for a living or give a presentation at a school or educational event.”

Peregrines have nested on PG&E’s rooftop most years since 2004. More than 45 peregrine fledglings have taken their first flights from the top of 77 Beale.

“Why they choose the nesting places they choose is such a big question,” Glucs said. “There are lots of other buildings around, but there’s something about the orientation of this building to the sun, the wind and the bay that’s perfect for them.”

Some of PG&E’s falcon hatchlings have gone on to maintain successful nests in other parts of the Bay Area. Phoenix, part of the 2011 clutch, pioneered a nest in Richmond, where he continues to produce young. And Grace, hatched in 2016, took over the nest at San Jose City Hall in 2020 and has produced two clutches, including four chicks who all survived their first fledge a year ago.

Between World War II and the 1970s, the peregrine population nearly disappeared due to toxic chemicals. But thanks to the Endangered Species Act and the good work of groups like the Santa Cruz Predatory Bird Research Group, the species has been saved. There are now about 350 pairs of peregrines in California.

In fact, California’s peregrine population may even be at “super-historic” levels — meaning the state may be home to more peregrines now than before the chemicals-induced decline, Glucs said.

The fastest animal species on earth, peregrines have a dive speed of more than 200 mph.

Glucs said her group is using data from the PG&E nest to determine whether urban factors, climate or individual bird physiology are influencing egg-laying dates, which have crept backward from mid-spring into mid-winter in recent years.

PG&E has partnered for more than 30 years with the Predatory Bird Research Group to protect the birds and has given the organization nearly $350,000 in charitable grants since the 1980s to promote environmental stewardship. PG&E will donate an additional $10,000 to the group in 2021.

Through its Avian Protection Program, PG&E supports other bird species across the company’s service area. Since 2002, the company has retrofitted nearly 38,000 poles to prevent bird strikes and electrocutions and has installed hundreds of platforms to serve as nests for ospreys.

The company is also supporting the planned spring 2022 reintroduction of condors in Redwood National Park on the North Coast. PG&E is working with the U.S. Fish and Wildlife Service to retrofit power lines to avoid condor strikes and provided a $250,000 grant to the National Parks Foundation in 2016 to help the reintroduction effort.

In addition to the Santa Cruz Predatory Bird Research Group, PG&E supports bird-advocacy organizations including the Ventana Wildlife Society, San Rafael-based WildCare, and Audubon and its Pacific Flyway initiatives.