Peregrine Falcons at UC Davis Medical Center
Updated June 21, 2021
Season 3 of what is affectionately known as “Keeping Up with the Peregrines” has ended. This year’s eggs brought forth three females and a male. We know three of the birds successfully fledged (meaning they had wing feathers large enough to successfully fly). However, several needed a little human help to get back into the nest during their early days of flight training.
Through July or so, keen observers may spot or hear one of peregrines flying around a nearby building or in the neighborhoods next to UC Davis Medical Center. A falcon expert from UC Santa Cruz banded the young chicks in early May (see more about the banding below), which might provide insights into their activities and habitats after they permanently leave the hospital area.
The livestream peregrine cam returns in Spring 2022 for Season 4, so stay tuned. In the meantime, watch the short video above about this season. For a review of what's happened around the nest over the past three years, read on:
Fly Away Home: Young peregrines test their wings
June 11 update: After emerging from their eggs in mid-April, the four peregrine falcons in this year’s nest were flight-ready at about six weeks of age. That’s why viewers haven’t seen them around the nest much lately. Now, at about nine weeks of age, the young falcons are spending more time away from the nest, flying around nearby building and trees.
The youngsters were clumsy flyers at first. A couple of them fluttered 15 stories down to the ground at the beginning of June and didn’t have the strength to get back to their nesting ledge. Fortunately, helping human hands – and an elevator – returned them to their rightful spot.
Peregrine parents will sometimes stop bringing food to the nest (known as an “eyrie”) to coax their young away from nest to encourage them to fly. Over the course of about a month, the parents will continue to feed them and teach them all they know about being a peregrine. Falcon experts call it “natal dispersal.” Some peregrines disperse early in that month-long window, some later. One of great peregrine mysteries is why some disperse very early, and others late.
At some point this month, the youngsters will venture out fully on their own and be completely gone from their nest by the end of June.
Another successful season for the peregrine falcon family
After a thrilling season in 2020, with a record five chicks, viewers of the medical center’s rooftop live cam saw another very active season around the nest in 2021. The first of four eggs appeared on March 10. Thirty-eight days later, three chicks emerged. On about April 20, a fourth peregrine chick arrived. All were very healthy and grew quickly in their first weeks.
In early May, a raptor expert from UC Santa Cruz visited the nest and banded the youngsters. It’s part of ongoing peregrine falcon research in the San Francisco Bay Area to help identify nest location choices and dispersal patterns for hatch-year birds. One of the parents of this year’s hatchlings is from a nest on the Rio Vista Bridge. Since that Delta community is part of the region being studied, the medical center’s birds were included in the Bay Area study. Watch our video to learn more about the research of these young falcons.
More about peregrine falcon chicks
Since at least 2015, peregrine falcons have made their home at the medical center. Their nest is located a safe distance from the hospital’s busy helipad.
Peregrine chicks change very rapidly once they emerge from their eggs. Weighing about 1.5 ounces at birth, the tiny chicks are feeble and slightly pink as their white downy feathers fill in. Since they can’t regulate their own temperature for the first week or so, a parent (mostly the mother) will stay with them to keep them warm.
Within five days, a chick’s weight will double. The siblings will continue to huddle and sleep in what looks to be a furry white pile. But they can also sit up and eat.
After about 14 days, the chicks will be walking around and eating with enthusiasm, as mom and dad fly in and out with tasty morsels.
Within three weeks, the chicks will be very active. By mid-June, they’ll be flying and leaving the nest. So, stay tuned for this season’s peregrine falcon saga.
A look back at Seasons 1 and 2
Last year (2020) was the most successful year for our peregrine falcon parents. They had a record-setting five hatchlings in April: three females and two males. Unfortunately, one hatchling didn't make it. However, the four young falcons were seen intermittently around the nest until late June. Get the recap from Season 2.
2019 was the first year the falcons were livestreamed. It was also a very successful year as the parents welcomed four youngsters. Livestream watchers enjoyed peregrine activities until mid-June, when the birds left the nest. Get the recap from Season 1.
About the Peregrine Falcon
The peregrine falcon was previously on the federal list of Endangered Species and was one of the first birds to be placed on California's Endangered Species List. The raptor was removed from the federal list in 1999, thanks to effort by The Peregrine Fund and others. The ban of DDT in 1972 across the U.S. also helped the species recover, leading to its removal from the state Endangered Species List in 2009.
Experts estimate the first-year survival rate for the chicks will be about 50%, as urban falcons face hazards such as injury, illness, and predators. The young birds typically begin flying away from the nest at the medical center sometime in mid-June. Experts say the birds usually stay in the area an additional month while their parents continue to feed them and encourage them to hunt.
Here are a few other facts about peregrine falcons:
- Scientific name: Falco peregrinus
- Body length: 13-20 in (33-50 cm)
- Wingspan: 31-48 in (78-122 cm)
- Weight: 1 to 3.5 lbs (0.4-1.5 kg)
- Like many raptors, peregrine falcon females are larger than males.
- Peregrine falcons can hit top speeds in flight of 200 mph and are considered the fastest animal on earth.
- Peregrines don't build typical nests like other birds, but instead lay eggs in a shallow indentation on the edge of a high cliff or other man-made structure, like a building or bridge.
- Baby peregrine falcons can start flying at 43 to 44 days old.
- Peregrines typically prey on small- to medium-sized birds, like songbirds, ducks, doves and pigeons. They are also known to feed on small reptiles, mammals and bats.