©2018 BY MAX WITHEY.

 
 
 

The Plunging Pelican

The first pelicans I encountered were on Isla Mujeres, jutting off the tip of the Yucatan peninsula into the Caribbean Sea. I approached one slowly on the beach, just to see what it would do. It turned to face me and stood absolutely still, staring over that huge bill at me. All it needed was a pair of spectacles perched on the end to complete the look. Suddenly nervous, I gave it some space. This large, awkward bird didn’t seem to give a shit about humans. Any closer and I felt that I’d receive an almighty peck. This thing was like a Brighton seagull on steroids.

 

The brown pelican (Pelecanus occidentalis) is one of those strikingly obvious animals. The size of its bill, which reaches down its long neck to its belly, hits you first. Standing at around a metre tall, and with a wingspan of two metres, they are impressively stout birds. Even so, they are actually the smallest of the eight pelican species that are found the world. Young pelicans mostly live up to the ‘brown’ description. Like seagulls, the plumage of younger remains brown until they reach sexual maturity. Their bodies then take on a silvery-grey hue, while the head goes a bright yellow-white.

On Isla Mujeres I mostly saw them sitting around and occasionally flying. It was in Puerto Escondido, Oaxaca, where I finally got to witness them in action. In the bay next to town, far to the west of where the world-class surfing happens, is a lovely little spot to swim and bathe. The water was calm and tourists frolicked in the sheltered bay. I grabbed some shade, ordered a cold beer, and looked past the bathers towards where the squadron of pelicans assembled by the anchored fishing boats.

 

The pelicans would bob around in the water, seemingly staring off into space, in their own little world. Then one would take off, casually flap its wings to gain height, a couple of mates following. Once they had flown about 50 metres the group began to loop back around. After circling back around to the spot they took off from, those huge beaks suddenly pointed to the water below. The wings tucked in and the body followed. The large and awkward pelicans transformed into a dive bombs and smash into the water. Their massive bills scoop up to 10 litres of water into a deep pouch, along with any fish unlucky enough to be hanging out in that spot.

 

Then the pelicans began diving right next to where people were enjoying the warm waters. I grabbed the GoPro and walked into the water. It took me about 30 minutes to eventually get the right spot, but patience yielded the following results:

The foraging behaviour I witnessed is only practised by the brown pelican and the Peruvian pelican. Other six species of pelican do not dive, but fish from the surface in large groups. The brown pelicans are not alone though when they embark on their fishing missions. Laughing gulls (Larus atricilla) shadow the pelicans and aggressively harass them as they emerge from the water. Before the pelicans can swallow their catch they must first pump out the litres of water they gulped up with the fish. It is during this moment of vulnerability that the gulls hope to pressure the larger birds into spilling some fish for them.  

Pelicans also forage offshore and join in one of nature’s spectacles - the feeding bonanzas known as bait balls. Along with dolphins, whales, tuna, gulls, and frigate birds, a feeding frenzy erupts when bait fish, such as herrings, anchovies or sardines, are pinned to the surface by predators. Pelicans join the aerial attack, plunging into their prey as dolphins swoop up from below.

Although they don't breed in the region of Oaxaca, they roost in the evenings in nearby mangroves. Breeding colonies are found further along the Pacificin isolated locations, and on many islands in the Gulf of Mexico. Even though they are recognised as seabirds, I did see some immature pelicans over 100km inland on a dam in Chiapas.

The brown pelican is found on every Mexican coastline, up both coasts of the USA, across the Caribbean, and down to Peru on the Pacific coast. As of 2006 the total population was estimated to be around 300,000 and in good health. Back in the 20th century the wide use of the pesticide DDT worked its way up the food chain to accumulate in pelicans, thinning the egg shells to the point of breaking and increasing adult mortality. Following the success of Rachel Carson’s book Silent Spring, which helped kick-start the environmental movement, DDT was banned in the USA in 1972. Since then brown pelican numbers have been consistently increasing and the species represents a conservation success story.

 

Current threats to brown pelican conservation include entanglement in fishing nets, lines and hooks, and of course the total contamination of the oceans by plastic. Oil pollution will remain an ongoing threat as long as it continues to be extracted from the sea-bed. The 2010 Deepwater Horizon spill killed an estimated 10% of all pelicans in the Gulf of Mexico.

Image source: IUCN

Along with these current issues, the uncertain future of climate change looms large for the pelican. In the northern Gulf of Mexico region, habitat loss is seen as the biggest threat to them. Brock Geary a postdoctoral researcher at the University of Louisiana-Lafayatte explained to me in an email: “The barrier islands where they nest in Louisiana are rapidly degrading, and I have seen multiple colonies physically disappear in the time I have been working with the species.”

 

Fortunately there is some hope on the horizon. Large scale ecological restoration projects are now being funded in the region for a variety of reasons, which will ultimately benefit the brown pelican.

With all these human disturbances putting pressure on brown pelicans, they cannot always rely on regular sources of food. The brown pelican has shown to be surprisingly adaptable to these anthropogenic pressures, according to recent research from Geary and his colleagues . They have found that fitter individuals within a population will go to greater lengths to reach more productive foraging grounds. Although these healthy birds become even fitter (the ‘rich get richer’ hypothesis), it is thought that over time whole populations will benefit as this information is transmitted throughout a colony.

Pelican art in Zipolite by unknown artist

Whatever the future holds for the charismatic brown pelican, hopefully they’ll weather the storm and provide us with plenty more serene experiences. In Zipolite I loved to watch pelicans gliding across the waves at sunset. They would float right along a wave as it builds, angular silhouettes on a blood orange background. They actually appeared to be having fun as they soared.

For extra information on brown pelicans check out the Smithsonian's National Zoo  and Oceana.

The IUCN Red List provides information and data on the ecology and treats to brown pelicans.

For research on brown pelican foraging behaviour the following papers are good places to start:

  • Condition-dependent foraging strategies in a coastal seabird: evidence for the rich get richer hypothesis (Geary et al, 2019)

  • Brown Pelican Foraging Success and Kleptoparasitism by Laughing Gulls (Schnell et al, 1983)