Channel Islands Falcons Face an Uncertain Future

It was barely light when I left my tent in Scorpion Canyon on Santa Cruz Island and ran west toward Potato Harbor. It was calm and cool, and my pace was steady. Right before I reached the harbor, I lit out on an old game trail.

Today it’s known as the Montanon Ridge Loop Trail, a scenic, 10-mile round-trip ramble on the southeast end of Santa Cruz Island. Besides views of Potato Harbor, the narrow track reveals the entire northside of the largest island off the California coast. 

A quarter mile southeast of the Potato Harbor junction, I loped along, gradually ascending rocky sections cloaked in colorful lichen and where Santa Cruz Island liveforevers thrive. I was running toward a rolling, serpentine spine that converged with Montanon Ridge. The route steepened and my pace slowed. 

At the time I couldn’t recall ever seeing anyone on this route, especially at dawn. However, as I worked my way up to a nameless, craggy ridge, my head was down when I nearly ran into a lone woman. I raised my head huffing and puffing.

“Have you seen any peregrine falcons?” she asked. “I’ve hiked over from the Navy site looking for them.”

“I haven’t seen any,” I replied, “but there is at least one pair that we see regularly between Potato Harbor and Scorpion Rock.”

She was a wildlife biologist clad with a backpack, notebook, camera, and binoculars and monitoring the whereabouts of these exceptional raptors, the fastest animal on the planet. Seeing one tuck its wings in a full dive at 200-plus mph is impressive to say the least. 

I left her to continue wandering for “The Wanderers,” appropriate I thought, as I continued with my slog 1,500 feet above Scorpion Anchorage. Peregrine is Latin for “wanderer.”

Grounded

Following the height of the California drought at the end of 2016, the high count was 51 individual peregrine nesting sites observed on all eight California Channel Islands. That number went down and continued to decline in 2022, when the last full survey was conducted. 

“The bare bones survey we did that year looked at 32 of those 51 sites on five of the eight islands,” said Nick Todd, wildlife biologist with the Center for Environmental Management on Military Lands. “For our effort, it was around 38 percent (active sites). This is a suggested significant decrease in occupied territories.” 

Peregrine falcons were an avian species affected by the pesticide DDT, forcing raptors like bald eagles and peregrines and seabirds like California brown pelicans to lay thin-shelled eggs that cracked during incubation. Over time, those species recovered from that manmade debacle, but they now face a new threat.

Coincidentally, the Highly Pathogenic Avian Influenza H5N1 (HPAI) strain also appeared in California in 2022. Although there is no direct evidence linking avian flu with the noticeable decline in peregrine falcons on the islands, according to Todd, the low occupancy rate seen this year on the islands is somewhat like the declines and low occupancy rate of peregrine populations from Monterey Bay northward to San Francisco Bay and into Western Nevada. 

“HPAI is a suspected culprit,” continued Todd. “Peregrines are one of the highly vulnerable species. We assume most falcons exposed to the virus perish within days of exposure.”

Susceptible to the Inevitable 

One of the prey items of peregrine falcons is waterbirds. From geese, ducks, shorebirds, and seabirds, species that travel great distances during their migrations are also prime carriers of HPAI. Those wild bird species are exposed to the virus by domestic birds like chickens and ducks.

“Peregrines aren’t a major spreader of avian flu,” said Joe Barnes, wildlife biologist for the U.S. Fish and Wildlife Service, and who has worked with peregrine falcons since 2004. “They are, however, vulnerable to high rates of exposure since they prey on many of the species that do readily carry the disease.”

Barnes said a lot of bird species can develop antibodies to fend off avian flu either to fight it off throughout their own populations or simply deal with it and not show major symptoms or die from exposure. He pointed to bald eagles as a species that has developed immunity against HPAI. 

Bald eagles and vultures in the eastern U.S. were initially impacted heavily as H5N1 first circulated, but they managed to develop antibodies that allowed them to cope and reach some level of population immunity.  

“For whatever reason, peregrines (and all other species in the genus Falco like kestrels, gyrfalcons, etc.) haven’t shown to develop antibodies to deal with H5N1, so they’re still highly susceptible and peregrines often die within one to three days of exposure or first showing symptoms,” continued Barnes. 

“Until, or unless, falcons’ immune systems develop antibodies in response to H5N1 exposure their best bet is for the strain to mutate enough so it’s not as lethal or is replaced by other less lethal and contagious strains.”

In mid-July 2026, I was loping along the North Bluff Trail between Scorpion Anchorage and Potato Harbor. Once I reached the edge of the cliff two newly fledged peregrine falcons sounded off from their lofty perch. Their grating “kak, kak, kak,” heard throughout the wave-battered cliffs. An avian sign of hope in an uncertain world.