(UC Berkeley photo by Maria Garcia Alvarez)

While expectant parents are always on pins and needles before the blessed event, some moms and dads prefer to be on pebbles or twigs.

Yes, Annie and Grinnell, the beloved peregrine falcons that have set up household atop UC Berkeley’s iconic Campanile bell tower, are ready to welcome three feathery bundles of raptor rapture.

Due date? This Thursday, April 25.

The highly anticipated triple hatching will — if Mother Nature plays nice with the timing — be captured on the Campanile’s nest cam and live streamed from 8:30 a.m. to 6 p.m. Thursday on the massive outdoor screen at the Berkeley Art Museum and Pacific Film Archive, BAMPFA, at Addison and Oxford streets in downtown Berkeley.

For the free viewing event, naturalists will be stationed at a booth throughout the day to provide expert commentary and answer questions as the peregrine chicks “pip” — raptor-biology-specialist speak for “break through the shell.”

And someone may be handing out chocolate eggs.

“The general rule of thumb to predict hatching day is 33 or 34 days from when the eggs were laid,” said Allen Fish, director of the Golden Gate Raptor Observatory. “Eggs are usually laid a few days apart from each other, so we went ahead and went with 33 days for the first one. Usually three eggs pip with 48 hours of each other.

“There’s always the tiniest possibility they’ll pull a fast one and do something different — nature is un-choreographable,” Fish said. “But Thursday will be our vigil. And I gotta say, I can’t wait to see what the eggs look like at five or eight feet high on that big screen!”

Arguably the most prominent members of the East Bay’s raptor community, Annie and Grinnell have made the Campanile their home since 2017, hatching two chicks that year and three in 2018. They now have a fan base across and beyond the Cal community.

They even have their own social media handles and have been posting periodic updates about their expectant family via Facebook, Twitter (@CalFalconCam) and Instagram (@cal_falcons). A livestream video of the nest is also available to the public 24/7 on YouTube at the UC Berkeley Campanile Peregrine Cam. Followers are encouraged to send their warm wishes to the happy couple using the hashtag #CalFalcons.

Peregrine falcons, the world’s fastest birds, have recovered spectacularly in North America thanks to the Endangered Species Act. While only two peregrine pairs were known to nest in California in 1970 – the population low – more than 400 pairs are estimated to flourish in the state today.

To bring this event to the Berkeley community, BAMPFA has partnered with the UC Berkeley Museum of Vertebrate Zoology, the Golden Gate National Parks Conservancy, the East Bay Regional Park District, the Institute for Wildlife Studies, and the Institute for Bird Populations.