“Brown pelicans have few natural enemies. Although ground nests are sometimes destroyed by hurricanes, flooding, or other natural disasters, the biggest threat to pelicans comes from people. In the late 19th and early 20th centuries, pelicans were hunted for their feathers, which adorned women’s clothing, particularly hats.
Several efforts in the early part of the 20th century were meant to curb the decline of brown pelicans. In 1903, President Theodore Roosevelt designated Florida’s Pelican Island as the first national wildlife refuge, a move that helped reduce the threat of plume hunters. Passage of the Migratory Bird Treaty Act in 1918 gave protection to pelicans and other birds and helped curb illegal killing.
During the food shortages following World War I, commercial fishermen claimed pelicans were decimating their industry and slaughtered them by the thousands. The nests were also frequently raided for eggs. With the advent and widespread use of pesticides such as DDT in the 1940s, pelican populations plummeted due to lack of breeding success. When pelicans ate fish contaminated with DDT, the eggs that they laid had shells so thin that they broke during incubation.
By the 1960s, brown pelicans had nearly disappeared along the Gulf Coast and experienced almost complete reproductive failure in southern California. Studies proving the pelicans were not harming commercial fisheries helped to stop their wholesale slaughter. In 1970, under a law that preceded the Endangered Species Act of 1973, the U.S. Fish and Wildlife Service listed the brown pelican as endangered, a term that means the species is in danger of extinction throughout all or a significant portion of its range. In 1972, the Environmental Protection Agency banned the use of DDT in the United States and restricted the use of other pesticides. Since then, there has been a decrease in the level of chemical contaminants in pelican eggs, and a corresponding increase in nesting success.”
