Linda Benedict | 5/5/2005 7:00:36 PM
The brown pelican, once extinct in Louisiana, has successfully been restored to the state. These birds are seen frequently all along the Louisiana coast and have been reported as far inland as Baton Rouge in recent years.
The brown pelican is primarily a fish eater and will consume up to 4 pounds of fish per day. It flies slowly above the water and will dive for a fish from as high as 70 feet. Most of the diet consists of “rough” fish, those not generally eaten by humans, including mullet, menhaden and minnow-like fish.
The brown pelican nests in large colonies on islands along the coast. Many nests are in shallow depressions surrounded by a rim of soil and debris. Others are in bushes or trees and made of a base of interwoven sticks topped by a mound of grass. Egg laying usually peaks in March and April, when two or three chalky white eggs are laid. The helpless young must be cared for and fed by the parents for at least the 75 days it takes them to fledge, or learn to fly.
Before the 1950s, the brown pelican lived in the approximate area it resides now. But by 1963, it was eliminated, mainly by the use of pesticides, especially Endrin, a DDT relative.
Florida brown pelicans were reintroduced into the state from 1968 through 1980 after DDT was banned. When the first pelicans were brought back, some were rendered flightless by clipping their wing feathers. This created a resident group that helped keep the free-ranging birds from dispersing too far from the release site. Within two years of the release, the first breeding attempts were documented.
The original release sites were on islands in Barataria Bay. Grand Terre received birds for nine consecutive years, 1968-1976; North Island received birds for four years, 1977-1980; and Queen Bess Island received birds in several different years. Some young were moved from Queen Bess Island to Last Island from 1984 to 1986. Three islands (Queen Bess, North and Last) became productive colonies and produced young that colonized another 12 islands by 2001.
From 1971 to 1992, 12,384 nests produced 18,547 fledglings (young birds that have reached the stage where they can fly) for an average of 1.5 young per nest. From 1993 through 2001, 103,727 nests produced 175,116 fledglings for an average of 1.65 young per nest. Eleven different sites have been used for nesting during these years, and seven different colonies were active in 2001.
Brown pelicans have relatively few natural enemies. Storms and high tides can flood the nests, but the birds will lay replacement eggs when nests are destroyed. Human disturbance on the nesting grounds can cause abandonment and must be monitored carefully.
The brown pelican recovery epitomizes a successful reintroduction program in wildlife biology. It shows that reintroducing species from other parts of their range into good habitat will allow the population to reestablish itself, once the contamination problem is solved. To maintain the population into the future will require a continual monitoring program.
(This article was published in the spring 2002 issue of Louisiana Agriculture magazine.)