Pelicans in the Piney Woods
By Dr. Jay
|Louisiana Ecrevisse, Boyce
During the cool months of the year, a truly amazing site is a flock of huge white pelicans spiraling upward above a piney woods reservoir or river, especially around locks and dams.
They rise on thermal air currents and rarely beat their black fringed wings. They appear and disappear depending on the angle of the sun. Once the rising air plays out, the pelicans set their wings and glide away toward their next destination. While white pelicans are found well inland from the Gulf Coast, large flocks can be found along the coast easily moving back and forth depending on weather conditions.
American White Pelicans are our inland pelicans breeding in the northern plains and wintering along warmer coasts in the South and California. Numbers declined greatly in the 1950s and 1960s as a result of accumulation of chlorinated hydrocarbon pesticides like DDT and Endrin from their fish and crustacean food sources. This interfered with breeding.
Pelican populations began to recover in the 1970s and by the 1990s there were good numbers of them again. Most folks were happy to see the birds but some werent.
About 20 years ago, catfish farming was pretty important in northeastern Louisiana. But, catfish farmers were suffering from heavy predation by Double-crested Cormorants. These water turkeys were a problem and kill permits were eventually granted by the U.S. Fish and Wildlife Service to assist farmers in protecting their crops. About that time, American White Pelicans found catfish ponds.
Back then, I was at an aquaculture meeting talking to a catfish farmer who volunteered that it took buck shot to knock down a pelican! There were no kill permits being issued for pelicans.
The pelicans would show up in the fall and left in the spring. Harassing the pelicans was the only legal way to keep them away from ponds.
Farmers found out the hard way that American White Pelicans can feed by feel. They would chase the pelicans away but find them greeting them early the next morning. After the farmers left at dark, the pelicans would return, gather together in a pond and form a living seine net driving the fish into a corner for mid-night snacks. Left unprotected, the catfish crop in a pond would be decimated while a farmer slept.
Today, there is basically no more commercial catfish farming in Louisiana and the industries in Arkansas and Mississippi are greatly reduced. Imports of Asian catfish hurt the catfish industry greatly but predation by pelicans and cormorants was a major contributor to the dramatic decline of catfish farming. In addition, pelicans brought parasitic worms to farms that adversely impacted survival and growth of fingerlings.
The American White Pelicans are huge being over 5 feet long with 8-9.5 foot wing spans.
Weight normally ranges from 10-20 pounds but extremes are 8-30 pounds! Their prominent yellow-orange bills have pouches that fill with water when they catch prey. The water is expelled and the food swallowed.
During the breeding season, a conspicuous projection/horn develops on top of a pelicans bill.
This is sloughed off once the eggs hatch.
The pelicans eat around 4 pounds of food a day. But, they dont carry their food to their nestlings in their pouches. Food is carried in the parents crops and regurgitated.
The American White Pelican uses its huge pouch for more than catching food. During hot weather, pelicans pant and lose body heat through the extensive blood vessels in their pouches.
How important is a pelicans pouch? Watch a resting flock of pelicans closely and youll see them regularly stretching their pouches to keep them pliable.