While peregrine falcons are feared predators in the wild, campus’s favorite birds may have a new enemy: drones.

A drone was spotted flying near the Campanile on Saturday morning, prompting a defensive response from Annie and Grinnell, the two beloved peregrine falcons who have nested in the Campanile since 2016. The flight may have violated campus’s policy on drone use, which indicates that pilots must receive prior approval from campus. The identity of the drone pilot is still unknown.

According to Mary Malec, a member of the CalFalcons team which monitors Annie and Grinnell, the falcons likely felt threatened by the drone infringing upon their nesting ground. While the pair do not have any eggs currently, they have raised 13 chicks together, according to CalFalcons.

“Peregrines will defend their territories from intruders and a drone is seen as an intruder,” Malec said. “They are most fierce at protection when chicks or fledglings are present and will readily attack a drone. They have brought drones down and drones have injured and killed raptors.”

Annie flew out from her nest toward the drone but did not hit it, although she has previously hit a drone in the air, Malec noted.

[email protected], the student organization for unmanned aerial vehicles informally known as drones, said none of their members have claimed responsibility for Saturday’s flight and they have no further information on the incident.

In a tweet reporting Saturday’s incident, the CalFalcons team emphasized the importance of keeping drones away from vulnerable wildlife due to potential danger and disturbance.

“Drones near falcon nests have caused nest site abandonment, injury, and death,” the tweet read. “The last thing any of us want is for Annie and Grinnell to get hurt or abandon the Campanile due to being harassed.”

Peregrine falcons were almost extinguished as a species in the 1970s prior to the federal ban of DDT, a pesticide known for its negative effects on the environment and birds such as falcons, according to the CalFalcons website. Since then, populations have worked to recover by adapting from their natural cliff habitats to skyscrapers like the Campanile.

Malec added Grinnell is particularly susceptible to disturbance at this time, having been injured in a fight with two other peregrines in October 2021, which resulted in a stay at the Lindsay Wildlife Rehabilitation Hospital.

“With Grinnell only recently recovering from his injury, we are hoping to keep them injury free, especially from human-caused dangers,” Malec said. “We can’t control other wildlife and their possible danger to Annie and Grinnell, but we can and must control human-caused dangers.”