A Magnificent Seabird The Brown Pelican (Pelecanus occidentalis)

By Dessi Sieburth

Brown Pelicans enhance the beauty of our California beaches. They are one of the most common and recognizable species along the coast of southern California. Their large size and exceptionally long bills make Brown Pelicans an unmistakable species. Adults have yellow heads and white necks, while juveniles have brown heads and necks. It takes several years for juveniles to attain adult-like plumage. On any beach, you are likely to see dozens of these magnificent birds hunting over the ocean, roosting on rocks, or flying in a V-shaped formation along the coastline. It is hard to believe that only 10 years ago, the Brown Pelican population was so low that the species was on the endangered species list.

Brown Pelicans range from British Columbia to northern Chile on the Pacific Coast, and from New Jersey to Guyana on the Atlantic Coast. In coastal California, the species breeds only on the Channel Islands (on Santa Barbara and Anacapa Islands), where about 6,100 pairs nest. Small numbers have bred inland at the Salton Sea in recent years, one of the very few inland breeding localities in the world for this species. During the non-breeding season, the coastal birds leave the islands and head for the immediate coast.

The primary diet of the Brown Pelican is a variety of fish. They catch these fish by diving into the water from heights of up to 60 feet in the air. As they dive, they rotate to the left, probably to avoid injuring their trachea and esophagus, located on the right side of their necks. This diving technique may be learned, and not instinctual, as adult birds can be up to 30 percent more successful than young birds at catching fish. Pelicans are well-known for their impressive throat pouches, which can store up to two gallons of water. After catching fish, pelicans will sit with their bills wide open for nearly a minute to filter the water out before swallowing. During this time, gulls will often pick fish out of the pelican’s open bill! The throat pouch of Brown Pelicans on the Pacific Coast is red, while the pouch of birds on the Atlantic Coast is black.

Pesticide use throughout the 1950s and 1960s was responsible for a rapid decline in pelican populations. Irrigation run-off from farms sprayed with pesticides ended up in the ocean, and the pesticides entered the food chain through fish, becoming concentrated in predators such as pelicans, eagles and ospreys.  The pesticide DDT caused pelicans to lay eggs with shells so thin that the eggs would break under the weight of the incubating parent. An even more deadly and less well-known pesticide, endrin, would kill pelicans directly. The Brown Pelican, the state bird of Louisiana, was extirpated from Louisiana by 1963 due to these pesticides. Once DDT was banned in 1972, and endrin in 1984, pelican populations quickly rebounded. The Brown Pelican has made a great comeback in Louisiana, and currently, 11,000 pairs of Brown Pelicans breed there. The Brown Pelican was removed from the endangered species list in 2009.

Although Brown Pelicans are a symbol of successful conservation, they still face many threats, and their populations need to be carefully monitored. Oil spills are the primary threat; when a Brown Pelican’s feathers become oiled, they are no longer waterproof, causing them to die of hypothermia or drowning. The Deepwater Horizon Oil Spill in the Gulf of Mexico caused an estimated 82,000 Brown Pelican deaths. Another threat is plastic; an estimated 90 percent of Brown Pelicans have plastic in their stomachs. When a pelican’s stomach becomes too filled with plastic, it can no longer store other food items in their stomachs, leading to starvation.

Brown Pelican populations along the Pacific Coast are being carefully monitored to record their recovery. Every year, in March and September, Brown Pelican populations from over 150 sites from Washington to Baja California are surveyed by the U.S. Fish & Wildlife Service, Cornell Lab of Ornithology, state agencies, Conservacion de Islas, and the Audubon network. In 2018, I participated in surveying Brown Pelicans around the Los Angeles Harbor, organized by wildlife biologist Bernardo Alps. A total of 20682 Brown Pelicans were counted along the Pacific Coast in September of 2018. To learn more about survey results please go to: https://ca.audubon.org/brownpelicansurvey. The next survey has been scheduled for September 12, 2020*, and to participate in a survey in California, please contact Anna Weinstein (aweinstein@audubon.org). These surveys not only help us monitor pelican populations, but they also help us get an idea about the health of our coastal ecosystems, because pelicans rely on healthy fish populations for survival and reproduction.

Thanks to Brian Small who provided some of the photographs for this article.

*please be aware of potential changes in dates because of Covid-19

References:

https://ca.audubon.org/brownpelicansurvey

https://birdsoftheworld.org/bow/species/brnpel/cur/introduction

Published by Los Angeles Audubon Society, Western Tanager, Sep–Oct 2020, Vol. 87 No. 1