A pair of beloved peregrine falcons that have made the top of U.C. Berkeley’s iconic Campanile bell tower their home hasn’t been seen since early January — and experts fear the spread of H5N1 bird flu could be to blame.
Annie and Archie, the parents to Aurora, Sol, Nox and the rambunctious Eclipse, would typically engage in pair bonding this month, readying the gravel nest box on the 307-foot-tall structure’s top. Interested parties can usually watch the area on a livestream shared by the scientists and volunteers at Cal Falcons. But, they’ve disappeared from the webcams, leaving just a panoramic view of the Bay Area and the city below.
“We can’t avoid their absence any longer, it’s just too glaring,” Mary Malec, a Cal Falcons raptor expert, told the university on Tuesday. “We have to say what the possibilities are, and what’s most likely.”
Cal Falcons addressed concerns about the raptors and their “abnormal” absence on social media earlier in the week.
“This is the first time we’ve seen such an extended absence from the tower,” the group said.
Annie typically lays her first egg in mid-March, although falcons in the northern California region can successfully nest as late as May or June. While it remains possible that Annie and Archie could still show up next month, they sought to address the “elephant in the room” that is bird flu.
“Aside from a couple of very brief sightings of a couple of other Peregrines on campus, it has been exceptionally quiet this winter. This is a marked contrast with the population three to four years ago, where there were regular intrusions at the Campanile by other falcons (called floaters),” they explained. “Floaters are a sign of a healthy population and ecosystem. The decrease in number of floaters is also an indication that HPAI is affecting not just breeding pairs, but birds looking for their own territories as well.”
So, have the pair succumbed to the virus? There’s been no evidence of a sick or dying bird at the tower. The last time they were seen they looked to be healthy. Volunteers have not found bodies at their favorite spots. They’ve also been searching Instagram photos and eBird reports.
“Nevertheless, it is possible that Annie and Archie have tragically succumbed to HPAI,” Cal Falcons said.
There are some other less morbid options to explain their disappearing act. They could be hunting off campus, have changed their territory due to the effects of the outbreak, larger predators could be responsible, or there’s another dynamic that is not understood.
They pointed out that studying wildlife only offers small snapshots into the cognition, decision-making, and lives of wild animals.
“We may never know…” Cal Falcons said.
Unless new raptors claim the Campanile, Cal Falcons says it’s not giving up hope that Annie and Archie will return. Annie was first seen at the tower in 2016. She’s had multiple mates since then and hatched 22 chicks.
Three of them are known to have died. Nox, one of her most recent eyasses, tragically passed away last year after a blood transfusion at UC Davis Veterinary Medical Teaching Hospital. He had previously undergone surgery at the facility for a broken wing.
