California Brown Pelican: Mysterious Deaths Despite DDT Ban

By Christian Paullin, Environmental Journalist

Editor’s note: In March 2020, Susan Deo told a triumphal story with stunning photos by Beverly Gates, M.D. (who, sadly, passed away in June): banning DDT allowed the endangered California brown pelican to thrive again. Unfortunately, the story didn’t end there.

If you’ve spent time on our coast you’ve likely seen the California brown pelican–a prehistoric-looking bird with a huge wingspan and a massive pouch below its bill–nosediving straight into the deep blue ocean. 

These majestic creature’s ancestors date back 30 million years. Despite being the smallest sub-species of pelicans worldwide, California brown pelicans (Pelecanus occidentalis californicus) are still quite large: up to four feet tall with wingspans over 6.5 feet.

They can dive bomb straight into the ocean from as high as 70 feet. A fall from that height would cause severe injury to a human, but pelicans are protected: air sacs protect vital organs upon impact and the birds contort their bodies to safely enter the water and protect their airways. Their dive is so ferocious it stuns fish nearby allowing the pelicans to collect prey into the billowing pouch and fly away. They can carry up to three gallons of water after gulping up their prey and eat up to four pounds of fish per day.

With a large appetite like that, California brown pelicans require a healthy ecosystem. Food scarcity, climate change, pollution, and habitat destruction, among other things, have all played a role in the declining population of these seabirds over the last 100 years. They are especially susceptible to oil; when coated, their feathers no longer insulate them, causing them to die of hypothermia or drown. 

Readers of Susan’s article know that a pesticide nearly led to the pelicans’ extinction. DDT weakened the pelicans’ eggshells causing their young to struggle to pass the incubation period. Their numbers plummeted and they were added to the endangered species list in 1970. By 1972, DDT was banned but it took another 35 years before populations recovered and the bird was removed from the list. This incident is cited as an example of how we can positively impact our environment and living things by enacting protective laws.

` Nevertheless, the California brown pelican is in near constant threat. In May of 2022, hundreds of the birds in Southern and Central California were found to be starving to death, severely injured, or already deceased. This incident has been deemed the “Brown Pelican Crisis” by the California Department of Fish and Wildlife and after thorough testing and autopsies, there is no indication of diseases or parasites. Food scarcity is thought to be the problem here. Birds likely injured themselves as they were desperate for food and willing to put themselves into more risky places in order to eat. All ages of these birds have been affected which also helps point to food scarcity as the cause of the crisis. As of now, many of the birds have been reintroduced to the wild but many died shortly after arrival and some are still in captivity recovering.

The California Department of Fish and Wildlife (CDFW) is asking for the public’s support in this crisis.

*First, it is most important to note that you should not touch or try to treat the birds yourself if you see a sick or dead pelican.

*If you do encounter a sick or injured pelican the CDFW requests that you contact your local Wildlife Rehabilitation Center listed at https://wildlife.ca.gov/Conservation/Laboratories/Wildlife-Health/Rehab/Facilities and email the CDFW at RehabWildlife@wildlife.ca.gov. Our closest center is International Bird Rescue in San Pedro.

*Report dead pelicans using the CDFW’s Wildlife Health Laboratory mortality reporting form to help monitor unusual mortality events. Please include photos if possible.

*And please donate to International Bird Rescue to help to keep our wildlife healthy and abundant.

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