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The California Brown Pelican: A Species of Moderate Concern

By Maria Pashos

Photographs by wildlife photographer Moose Henderson

Male California brown pelicans seek out nesting sites where they know their female counterparts will have gathered for mating season. Much like human men, the brown pelican will then put on a mating display or performance. This performance is mainly composed of movements that showcase the male’s bright red gular pouch. Once they’ve succeeded in attracting their mate, they devote themselves to foraging for twigs so that the female can weave together a safe and comfortable nest for their soon-to-be eggs. 

Brown pelican nesting season spans from January through October. However, nesting seasons in the late 1950s to the early 1970s were particularly short. This was because, for many pelican couples, the newborns never hatched.

Due to a lack of pesticide enforcement regulations during that nearly twenty-year span, the chemical DDT so impacted the food chain that eventually, microorganisms that predominantly enter the ocean via waterways were consumed by fish and wildlife, in turn becoming highly toxic. With mackerel, sardines, and anchovies being the brown pelican’s main food source, it wasn’t long before a large majority of the pelican population was also contaminated. A second pesticide, Endrin, which was carried by irrigation and rainfall from fields into the ocean, was so toxic that adult brown pelicans would die quickly after consumption. 

The most tragic consequence of DDT contamination came in the form of fragile, weak eggshells that would break under the weight of the incubating parent, a symptom that swiftly took a toll on the pelican population. Reproductive success rates among pelican couples dropped so low that in 1978, after years of DDT exposure, there were only 466 nests found along the California coast, a far cry from the celebrated 6,000 nests discovered in 2004 following years of pesticide bans and careful population monitoring, which yielded a significant resurgence in the pelican population.

Although DDT use was widely banned in 1972, it would be thirty-seven years before the California brown pelican would officially be removed from the federal endangered species list on November 9, 2009.  The conservation efforts that went into restoring the pelican population yielded a true victory for all organizations involved, but most notably for the Environmental Defense Fund (EDF), which was made up of scientists who took notice of the effects of DDT on fish and wildlife and had firmly resolved to contribute to the movement for banning toxic pesticides. 

Despite this victory, the California brown pelican is still considered a vulnerable species by conservation scientists, as a considerable amount of careful monitoring and human intervention is required in order to maintain the current population. In recent years, the pelicans have faced new challenges to their survival, resulting in large numbers of starving pelicans appearing on the Southern California coastline. Although experts are still trying to establish the root cause of this mass starvation, we do know that miles-long pockets of above-average temperature surface waters in the Pacific are partly to blame. Bait fish are especially sensitive to temperature changes and are instinctively avoiding these waters by moving deeper, resulting in a severe scarcity of fish for the pelicans, who, although capable of diving as far as six to ten feet deep for their prey, are coming up short.

Just this past spring, a large number of emaciated and dehydrated juvenile pelicans arrived in California and the Gulf of America. Organizations like the International Bird Rescue (IBR) have been working tirelessly to recover and revive these young birds while also collaborating with biologists to understand why starvation is so concentrated in this age group. The leading theory seems to be that the high-temperature surface waters are once again to blame. However, in addition to causing bait fish to avoid coastlines where pelicans nest, the temperatures are also the cause of other harmful threats to these birds. Toxic algae growth and outbreaks of Domoic acid and Saxitoxin, are consumed by fish, and much like the pesticides that harmed the pelicans in past decades, are now poisoning adult pelicans upon consumption. This leaves juvenile pelicans to fend for themselves under already difficult conditions, and with only limited hunting knowledge. 

In a little over a century, we’ve been able to observe how the unregulated use of pesticides and extreme temperature fluctuations in ocean water can cause widespread havoc on whole ecosystems and bring entire species to the brink of extinction. As such, the California brown pelican’s resilience deserves acknowledgment. While the pelican isn’t uniquely threatened by these factors, the species is unique in one very significant way: scientists believe these dinosaur-like birds have existed for nearly 36 million years, and quite impressively, they haven’t undergone significant physical changes.

Where other animals have evolved to meet the challenges of an ever-changing planet, we know from the study of pelican fossils that they have remained largely unchanged. It’s important to stress that this is not an indication of genetic inferiority; to the contrary, scientists have been impressed by the pelican’s sheer resilience and seeming needlessness to evolve. Although we must continue to keep a close eye on their numbers and provide aid where we can, luckily for us, the California brown pelican is a species that clearly intends to stick around.

The California Brown Pelican

By Maria Pashos

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