Grinnell, one half of the popular Peregrine falcon pair nesting at UC Berkeley, was found dead last year. His mate Annie has carried on, hooking up with a new suitor atop the Campanile. (Image courtesy of Cal Falcons/Twitter)

As four new falcons hatch from their eggs next week at University of California at Berkeley’s famous bell tower, a plan has been hatched for a watch party on the campus Tuesday to celebrate the occasion.

The first of four eggs of a peregrine falcon named Annie and her new mate Lou is expected to hatch sometime between 8 p.m. Monday and 5 a.m. Tuesday in a nest atop UC Berkeley’s Campanile tower, where Annie has made her home for several years. That’s according to Cal Falcons, the group of scientists that monitors the falcons and posts regular photos, commentary and memes about them onto social media.

After Annie and her late mate Grinnell made their home in the Campanile in 2017, a crowdfunding campaign in 2019 led to the installation of two webcams that live-stream the nesting area and balcony to the public 24/7.

On Tuesday, the UC Berkeley Art Museum and Pacific Film Archive (BAMPFA) is hosting a Hatch Day celebration where the falcon cam will be broadcast live from 9 a.m. to 5 p.m. for free on an outdoor screen as eggs hatch. A team of falcon experts will also share information and insights about the birds during the event.

Cal Falcons wrote in an update Friday that signs of eggs starting to hatch may happen as early as Saturday evening.

“Inside the eggs, the chicks will be working on piercing internal membranes and then cutting a tiny crack in the shell (called a ‘pip’) that will let the chick breathe air for the first time,” the group wrote.

The chicks’ mother Annie has had an eventful past year.

According to UC Berkeley, in March 2022, Annie’s longtime partner Grinnell was found dead on campus. Eggs Annie laid before Grinnell’s death would not have hatched except for the arrival of a new falcon, eventually named Alden, that helped incubate the eggs.

Grinnell, one of the beloved Peregrine falcons, who along with his partner Annie, nests on the UC Berkeley Campanile Tower, was brought to Lindsay Wildlife Rehabilitation Hospital in Walnut Creek on Oct. 28, 2021, with injuries after a suspected territory dispute with another falcon. (Photo courtesy of Dr. Krystal Woo/Lindsay Wildlife Experience via Bay City News)

Two hatched that were named Grinnell Jr. and Lindsay, named after Walnut Creek’s Lindsay Wildlife Experience that took in Grinnell for rehabilitation after he was found injured in a 2021 tussle with rival falcons at the Berkeley Tennis Club.

Lindsay then was found dead in August from an apparent attack by a red-shouldered hawk. Annie’s new mate Alden then left in November and was not seen again by the Cal Falcons group.

That allowed the latest mate to swoop in, and a naming contest held by the school this February left him with the name Lou, a reference to Louise Kellogg, a UC Berkeley alumna who was the partner of Annie’s namesake, the naturalist Annie Alexander.

More details about the hatch party for Annie and Lou’s chicks can be found here.

The live-stream of the nest, for those who can’t make it to the party in person, and social media updates on the hatchings and other information about the falcons can be found at Cal Falcon’s website.

Dan McMenamin, Bay City News

Dan McMenamin is the managing editor at Bay City News, directing daily news coverage of the 12-county greater Bay Area. He has worked for BCN since 2008 and has been managing editor since 2014 after previously serving as BCN’s San Francisco bureau reporter. A UC Davis graduate, he came to BCN after working for a newspaper and nonprofit in the Davis area. He handles staffing, including coaching of our interns, day-to-day coverage decisions and management of the newswire.