Brown pelicans are starving across California. Wildlife experts think they know why

San Francisco Chronicle​

26-04-2025

JD Bergeron felt the dread return this spring when worried volunteers kept showing up at International Bird Rescue's wildlife facilities with starving brown pelicans.
It's happening again, Bergeron thought.
For the third time in four years, brown pelicans around California appear to be ailing. Over the past month, more than 100 malnourished and struggling birds have been brought to the nonprofit's Bay Area and Southern California wildlife centers, said Bergeron, International Bird Rescue's CEO.
The birds are arriving listless and starving, and are being found in places out of their habitat: parking lots, backyards and even a tattoo shop. Many sport additional injuries, probably caused by fishing hooks or lines.
'There's been semi-regular problems with brown pelicans,' he said. 'These large population crashes result in lots of birds coming in for care. Fortunately, many can be saved.'
Bergeron and others believe climate change is warming water close to the ocean surface — sending the fish that pelicans eat deeper and out of their reach, leading to skinny, malnourished and disoriented birds.
The phenomenon marks a potentially worrying setback for a species that has struggled over the years and spent decades on the endangered species list due to exposure to DDT, a synthetic pesticide that weakened eggshells, causing their breeding numbers to plummet. It wasn't until 2009 that brown pelicans were removed from the list.
Last year, the Bay Area rescue center and its Southern California counterpart treated hundreds of malnourished pelicans, which wildlife officials attributed to a late spring storm that made fishing extremely difficult for the birds.
A similar starvation happened in spring 2022, when almost 800 pelicans were admitted into wildlife facilities and close to 400 were returned to the wild, according to the California Department of Fish and Wildlife.
This year's wave of malnourished pelicans came as the bird sanctuary was already dealing with an onslaught of birds suffering from poisoning from domoic acid, caused by algal blooms.
Then, dozens of young pelicans started arriving at International Bird Rescue's wildlife centers. By the end of March, the center was treating 41 birds, including many that hatched this year, Bergeron said. Large numbers of fledgling pelicans can point to a strong breeding year, but he and others worry that the domoic acid bloom may have poisoned parent pelicans, causing fledglings to leave their nests in search of food.
More pelicans kept arriving in April, but many of those did not seem to be suffering from domoic acid, he said.
'It took us a minute to realize, 'Uh-oh, it's transitioning,'' he said. 'We were nervous, having had challenges in 2022 and 2024, we thought, 'Maybe this is something cyclical,' but … this happening the very next year wasn't on any of our radars.'
Bergeron and others are concerned that fish are swimming deeper to escape warming ocean waters, out of pelicans' reach. Other animals that eat the same fish don't seem to be suffering.
'There are changes in the ocean resulting in pelicans not being able to feed the way they historically have,' he said.
Now, the birds are gorging — they can eat their body weight in fish every day — and the influx of birds has Bergeron's staff working long hours, scrambling to make sure it has enough food, medicine and other supplies to care for its patients.
'We're clearly not out of the woods,' Bergeron said. 'We need to dig deeper and figure out what are the root causes of this problem and how do we fix that.'