California Has a Theory on Why Brown Pelicans Are Starving and Dying

Emaciated brown pelicans are washing up on California shores in the hundreds. State officials and researchers aren’t sure why, but they think it could be weather-related.

The state’s working hypothesis is that this situation, similar to what happened in 2022 when nearly 800 starving pelicans were rescued, was likely caused by late spring storms hitting the coast.

“The waters were incredibly choppy, it was very windy, visibility was poor,” said Tim Daly, spokesperson for the California Department of Fish and Wildlife. “Our strongest belief at this point is that the pelicans were simply having trouble reaching the fish that were below the surface.”

He said there are plenty of fish and noted that anchovies are particularly abundant this year. The pelicans just can’t find them in the murky water.

Monterey Bay is a particular hotspot in the state’s rescue effort. The Wildlife Rescue and Rehabilitation Center at the SPCA of Monterey County has taken in more than 100 famished birds over the past month. Staff there have dedicated two outdoor enclosures to the pelicans and converted a staff bathroom into a heated recovery room for birds that can’t regulate their body temperature. Rescue calls started coming in on April 19 and have not yet stopped.

Ciera Duits-Cavanaugh, manager of the wildlife center, said the birds are arriving at half the weight they should be and that most rescues are happening on piers.

“[The birds are] targeting places where there’s easy food, so boats that are off-loading fish onto docks, restaurants — anywhere that they can get a hand-out,” Duits-Cavanaugh said.

Cory Utter, the senior wildlife technician at the wildlife center, said they likely are not saving all the pelicans because most people can’t tell if a bird is struggling. There is one sure sign, though.

“If you can walk right up to it, and it doesn’t seem bothered by you, then there’s probably something wrong,” Utter said. Officials recommend people call local wildlife centers if that happens.

Last week, a mom and her young son reported a weak-looking pelican drooping its beak into a tide pool at Asilomar State Beach in Monterey County. Two SPCA volunteers crouched down on the rocks, scooped up the bird, and placed it in a dog crate. The pelican didn’t resist. After a short drive back to the wildlife center, the volunteers pulled out the crate. The bird’s eyes were open, but its head was cocked to one side, and it was motionless. It had died in transit.

Storms may be to blame

Rebecca Duerr, director of Research and veterinary science at International Bird Rescue, said the explanation that early spring storms limit the bird’s ability to find food makes sense, especially since they’ve tested dead pelicans and ruled out avian flu as a possible cause.

“Certainly, the visibility and catchability of fish can be an issue for them because they don’t dive very deep — even the biggest brown pelican can only grab fish about 6 feet deep,” she said.

About one-third to a half of the starving pelicans arriving at rescue centers were injured, she added.

“I think that brown pelicans take more risks in their feeding — more likely to go after fishing gear and that sort of stuff — when they’re nutritionally stressed,” Duerr said. “A desperate, hungry pelican can get into trouble.”

After an odd weather event in 2010, she said, they were found landing in people’s yards and snatching food off of hot barbecue grills.

Pelicans back from the brink

California brown pelicans almost went extinct in the 1970s. Researchers found that the toxic chemical DDT entered coastal waters, where it was absorbed by the fish pelicans eat. The chemical changed the calcium metabolism in the birds’ bodies, which made them lay eggs with shells too fragile to withstand the weight of incubation. After DDT was banned, the pelicans recovered and were removed from the endangered species list in 2009.

Brown pelicans’ largest breeding colonies are in the Channel Islands and Baja California, Mexico. Nesting season peaks in March and April, and newborns typically arrive in the Bay Area around May. But Duerr said most of the starving pelicans she’s seeing are older.

“The Channel Islands colony, we know, has done a lot of chick abandonment, so there probably won’t be any fledglings arriving,” Duerr said.

Daniel Anderson is a retired professor from UC Davis who has studied brown pelicans for over 50 years and helped prevent their extinction. He’s planning to check on the Baja colony this month, but he said he’s not optimistic after seeing how they fared earlier this year.

“The breeding birds in the Gulf of California are failing miserably,” Anderson said. “Where there would be 20-30,000 nests, this year there were way less than 1000.”

Anderson said the Baja population declined in 2014 during the marine heat wave scientists called “the blob” and has not really recovered since. He also said the pelican population tends to follow the El Niño and La Niña sea surface temperature cycles — doing worse with warm El Niño conditions and better with cold La Niña conditions.

California experienced a rare three-year run of La Niña from 2020 to 2023 before El Niño in 2024.

The National Oceanic and Atmospheric Administration predicts we’ll enter neutral conditions soon and may see La Niña emerge this summer. “The surface fish like anchovies, sardines seem to be more available to surface-feeding seabirds during La Niña conditions,” Anderson said.

As climate change is expected to make El Niño cycles more intense and frequent, Anderson said pelicans may gradually move north to breed. “It’s a complex situation, and it’s dynamic and moving really fast.”