Species of Special Concern, Criterion #1 (SSC 1)The brown pelican is listed as a species of special concern based on its vulnerability to habitat modification and human disturbances (e.g. Schreiber & Mock 1988; Klein et al. 1995). These factors may threaten the species in the absence of effective management and conservation strategies (FWCC 2009). Threats & Conservation: Once thriving throughout its range, populations of the brown pelican began to decline in the late 19th and early 20th centuries as the result of plume hunting and slaughter by fishermen who viewed the birds as competition for valuable catch (USFWS 1995). In 1903, President Theodore Roosevelt designated Pelican Island on the Indian River Lagoon as the first national wildlife refuge, reducing the threat of plume hunters in the area. Further protection was established by the passage of the Migratory Bird Treaty Act of 1918, and enhanced when studies revealed that brown pelicans were not detrimental to commercial fish stocks. Unfortunately, pelican populations began to decline again in the mid 20th century from poor reproductive success linked to the widespread use of toxic pesticides like DDT and dieldrin. Studies found that these chemicals were transported by water (irrigation and/or rain) from treated agricultural areas into pelican feeding grounds located in nearby estuaries and coastal waters (Terres 1980; USFWS 1995). Pesticides ingested from contaminated prey items resulted in disruption of calcium metabolism in pelicans, leading to eggshell thinning and subsequent loss of young from egg damage. In 1970, the U.S. Fish and Wildlife Service listed the brown pelican as an endangered species, which was followed shortly by the banning of DDT and the restriction of similar pesticides by the Environmental Protection Agency in 1972. By 1985, improved breeding success led to population growth that allowed the brown pelican to be removed from the Endangered Species List in Alabama, Florida and along the entire Atlantic coast (USRWS 1995). In November 2009, the bird was delisted as an endangered species across the remainder of its distribution (Federal Register 2009).Recovery efforts are ongoing to increase pelican populations across their natural range. These programs include continued banding and census of existing birds in order to plot migration patterns and gather data on lifespan and growth rates, as well as the patrolling of rookeries and sanctuaries to minimize human disturbance to nesting sites in these designated areas.
No one has provided updates yet.