Cal Falcons

We had an unknown female visiting the tower this afternoon. Hopefully we'll start to see more exploration of the Campanile soon!

To Annie: your patience, care, and tenderness were a beacon of joy and hope in our world.

We miss you.

This is the first year since Cal Falcons started up that we haven't been celebrating by watching Annie stuff bloody hunks of pigeon meat into the ravenous gullets of a pile of fluffy falcon chicks. But even though we're missing our beloved Annie this year, we wanted to honor all the moms out there.

It is estimated that the environment provides approximately $150 trillion of economic benefit every year for free (Jiang et al. 2021). The Peregrine Falcon and Bald Eagle are just two of many stories that demonstrate the power of regulation to preserve the world that we all live in and depend on.

In some cases, the damage could be irreversible, as many endangered species could very quickly go extinct without protections.

Environmental regulations protect not only plant and animal species but every person on the planet through clean air and water.

The recovery of these species is due almost entirely to legislation that is scheduled to be officially “sunset” by Executive Order dated 9 April 2025 (“Zero-based Regulatory Budgeting to Unleash American Energy). The damage that this could cause could take decades of effort to recover from.

the Endangered Species Act (ESA), Migratory Bird Treaty Act (MBTA), and Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), there are currently ~5,000 Peregrine Falcons and ~300,000 Bald Eagles in the lower 48!

Due to the use of DDT and other pesticides, there were fewer than 100 Peregrine Falcons in the lower 48 United States in the 1970s. Bald Eagles had dropped to fewer than 1000 individuals across the same area. Thanks to the effects of science-based environmental regulations such as...

Read the full study here: bit.ly/AnnieSciencePaper

And press release here: bit.ly/AnnieScienceRelease

UC Berkeley researchers just published a paper about conservation funding featuring Annie as a case study!

They found that messaging can have a dramatic effect on donor sentiment, and that Annie's story led to positive associations.

Not yet. Occasionally we see a bird, but no one regularly

What have Berkeley's falcons meant to you?

Gretchen Kell from UC Berkeley's news office is looking for personal anecdotes with specific examples of how Annie and company have impacted your life/health/awareness, during the pandemic or any time.

Email her at gkell@berkeley.edu

We just had a new falcon visiting the Campanile for 15 minutes or so. Fingers crossed it will continue to hang out and get to know the area!

Based on head, bill shape, and skin and feather coloration, it appears to be a new bird.

#peregrinefalcon #urbanwildlife #cal #berkeley #gobears

Looks like a red-tailed hawk! Nice.

Yes, they’re starting to see more and more birds with antibodies. Hopefully immunity will continue to build.

UC Berkeley falcons Annie and Archie are missing. Is avian flu the cause? - Berkeley News Cal Falcons says it's likely, as the pair hasn't been seen in nearly two months, and the disease "is hitting peregrines very hard right now."

As avian flu continues to kill birds worldwide, @calfalcons.bsky.social says the disease "is hitting peregrines very hard right now,” and is likely why UC Berkeley’s resident falcon, Annie, and her mate, Archie, haven’t been seen on campus in nearly two months. news.berkeley.edu/2025/02/24/u...

Annie may have simply decided she no longer likes the taste of pigeon and wants to spice things up with some sandpipers. We may never know...

We will try to keep you all updated as we learn more!

4) Some other dynamic is occurring that we don't understand

Studying wildlife is an exceptionally difficult field. We are afforded only small snapshots into the lives of wild animals. Animals are complex and there could be any number of factors at play in any particular observation.

3. Predation. -There are many predators out there, such as Owls or Eagles, that will prey on a Peregrine when the opportunity presents itself. We have seen large raptors in close proximity to the Campanile in the past, and we can't rule out the possibility that they have caused this disappearance.

Peregrine Falcons are often highly wedded to the territory location, but they do change spots if the nesting environment is not ideal. This is not a very likely scenario, but is possible.

2) Annie and Archie are changing their territory/nesting location due to the effects of HPAI. With substantial numbers of territories empty right now, it's possible that Annie and Archie are exploring options for breeding, maybe even looking for a different mate as pairs lose their partners

Other options for what's happening right now are as follows:

1) Annie and Archie are totally fine and just hunting off campus and will return to the nest when they're ready. We've seen Annie disappear from the Campanile before. Perhaps she's just off in a new spot before returning to the Campanile.

Have Annie and Archie succumbed to HPAI? We've seen no evidence of a sick/dying bird at the tower, and the last time Annie and Archie were seen, both looked to be healthy. Volunteers have checked for bodies at many of their favorite roosts and have not found anything, but it is still possible

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. It could take some time for younger birds to fill open territories.

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 3-4 years ago, where there were regular intrusions at the Campanile by other falcons (called floaters).

In some parts of the Peregrine’s range, nearly 50% of historic territories are unoccupied due to this disease and case positivity rates are pushing 80%. Locally, approximately 40% of the peregrine territories here in the Bay Area are currently unoccupied, leaving a lot of unclaimed space.

This virulent and deadly disease is incredibly dangerous to many groups of birds, including shorebirds and raptors. In some species and for some strains of the disease, mortality is over 90% for infected individuals. It is hitting Peregrines very hard right now in some parts of the world

However, this absence is abnormal and it's worth taking a moment to lay out the possibilities of what's going on based on what we know.

First of all, we have the elephant in the room: highly pathogenic avian influenza (HPAI).

This is the first time we've seen such an extended absence from the tower. Although concerning, it is certainly possible that Annie and Archie may show up next month. Our typical first egg has been in mid-March, so there's still a huge open window for breeding to occur this year.

Hi everyone,

All three cameras are back in operation, including the upgraded South/West camera.

We also wanted to take a moment to talk about how quiet things have been on this site and also at the Campanile. Neither Annie nor Archie has been seen at the Campanile since early January.