Grinnell, the campus’s beloved male peregrine falcon, was found injured southeast of campus on Oct. 29 following a fight with a pair of peregrine falcons and is being treated at the Lindsay Wildlife Rehabilitation Hospital in Walnut Creek. The incident is raising questions about whether he and Annie, his longtime mate, who likely also was there during the attack, can hold onto their home atop the Campanile, where they’ve raised their young for five years.
“It is possible that the new pair is trying to take over the territory,” said Mary Malec, a member of Cal Falcons who monitors local raptor nests for the East Bay Regional Park District. “In other territories, sometimes the fight ends with one skirmish, and sometimes the fights last over many days.”
Malec said fights between peregrines often result in serious injury. Grinnell, who was identified after being found because he is banded, did not suffer broken bones, but the tip of his upper beak is broken. He also has a wound on his head and on his right foot and left wing, is missing feathers under his chin, and suffered abrasions.
“He is alert … and expected to recover,” she said, adding that the missing piece of his beak can grow back. Veterinarians at the rehabilitation hospital will determine when he can be released, and Malec said Cal Falcons will “seek out the advice of the Predatory Bird Research Group at UC Santa Cruz on how to return Grinnell to campus.”
Cal Falcons is a joint effort by several bird experts who represent UC Berkeley, Golden Gate Raptor Observatory, East Bay Regional Park District, the Institute for Bird Populations and the Institute for Wildlife Studies.
Malec said that Grinnell’s homecoming “depends on his healing” and whether he can hunt and provide for himself and Annie, but that peregrines “have a strong territorial drive and have been known to go back to their nesting territory after rehab.” At age 8, Grinnell also is in the prime of his breeding years, she added.
The falcons that attacked Grinnell likely were not Annie and Grinnell’s offspring, she said. Since 2017, the pair has produced 13 chicks — four females and nine males; one, Lux, died as a fledgling after she struck a window.
“We know the male (in the skirmish) is not banded, so it is not one of (Grinnell and Annie’s) offspring,” said Malec. “We haven’t gotten a good look at the legs of the (attacking) female yet. But Annie has had only a couple of female offspring, and we know where one is, and it isn’t her, and the other is quite large, and this female is smaller than Annie — just a guess it’s not an offspring.”
As for Annie, Malec said that the pair of falcons that attacked Grinnell were at the tower again yesterday, and that Annie was seen chasing them around. Many of the falcons’ activities on and near the tower can be glimpsed via three webcams, but Malec said observations also are being made from the ground.
“I would say that Annie is in danger,” said Malec. “Since it’s a pair of peregrines, … she is in even more danger than if challenged by only one peregrine.”
This morning, Annie was “interacting with one of (the peregrines) on the west ledge” of the tower, she said.
Peregrine pairs do stay together for life, but Malec explained that if one dies or is unable to return after injury to its territory, “the remaining falcon is very likely to find a new mate. New mates have appeared on territory sometimes within days of the death of a breeding peregrine. We know there are floaters — non-breeding adults waiting around for a territory — nearby.”
Even if Grinnell returns to the Campanile nesting territory, “there could be a battle for the territory, and the one best able to defend itself would likely be the one to breed,” she said.
“This is not easy to talk about, and not at all easy to report to Annie and Grinnell’s fans,” Malec said in a Cal Falcons Facebook post on Sunday. “We are all hoping for the best.”
Lynn Schofield, a member of Cal Falcons and a staff biologist at the Institute for Bird Populations, said “it hurts to know Grinnell has been injured, but good to know that there is a whole world of peregrine falcons out there living as wild animals.
“Considering that the species was almost lost from the U.S. not all that long ago, the fact that we not only have Annie and Grinnell nesting in Cal’s backyard, but that they have competition, really speaks to the comeback the species has made. The recovery of the peregrine falcon has gone further than preserving a handful of individuals, but it has succeeded to the point that we are now seeing dynamic interactions between an entire population of the species.”
Malec suggests that fans of UC Berkeley’s falcons who want to help consider supporting Lindsay Wildlife Experience and also urges them to follow Cal Falcons on social media and not call Lindsay for updates about Grinnell, as its team is “busy treating and caring for other animals. We promise to update you with new information.”