Marco Island Wildlife:The Brown Pelican
The Brown Pelican
The Brown Pelican is a has an oversized bill and can be quite elegant and comical to watch. They glide above the Gulf waters rising and falling with the waves.
Brown pelicans are impressive divers, circling up to 60 feet above the surface before plunging headfirst underwater in search of food. This magnificent bird's trachea (windpipe) and esophagus (tube connecting throat and stomach) are located on the right side of its neck. A foraging pelican spots a fish from the air and dives tucking and twisting to the left to protect its trachea and esophagus from the impact. As it plunges into the water, its throat pouch expands to trap the fish, filling with up to 2.6 gallons of water. Pelicans usually feed above estuaries and shallow ocean waters within 12 miles of shore, but sometimes venture over the deeper waters past the narrow continental shelf of the Pacific coast. They occasionally feed by sitting on the surface and seizing prey with their bills, like other pelican species, usually when a dense school of fish is close to the surface and the water is too shallow and muddy to plunge. They also steal food from other seabirds, scavenge dead animals, and eat invertebrates such as prawns.
Though they have an awkward gait on land, Brown Pelicans are strong swimmers and masterful fliers. They fly to and from their fishing grounds in V-formations or lines just above the water’s surface. Pelicans usually forage during the day, but may feed at night during a full moon.
Highly social all year, pelicans breed in colonies of up to several thousand pairs—usually on small islands where they are free from terrestrial predators. The male defends a nest site and nearby perches for up to 3 weeks until he attracts a mate, and the pair is monogamous throughout the breeding season. The parents incubate their eggs with their feet. If disturbed suddenly they fly hastily, sometimes crushing their eggs. Pelicans regurgitate predigested fish onto the nest floor for their nestlings, later switching to whole fish once the young are big enough. The young can fly and fend for themselves after 3 months, but take 3–5 years of age to reach sexual maturity.
Brown Pelicans are a living symbol of how successful wildlife conservation can be. They nearly disappeared from North America between the late 1950s and early 1970s because of pesticides entering the food chain. The pesticide endrin killed pelicans outright, while DDT contamination led to thin-shelled eggs that broke under the weight of the parents. In 1970, Brown Pelicans were federally listed as endangered. The plight of pelicans and other species led to a ban on DDT in 1972 and a reduction in endrin use, allowing pelican numbers to rise. By 1985, numbers along the Atlantic and eastern Gulf coasts had recovered enough to delist those populations.
The populations of brown pelicans continue their overall strong increases since the 1960s, though pelicans still face human-caused threats. Disturbance from human activity in their coastal nesting habitats can cause problems, as panicked pelicans often abandon or accidentally destroy their nests. The brown pelican is protected by the Migratory Bird Treaty Act. Abandoned fishing line also threatens this species along with many marine animals. It has been estimated that more than 700 adult and immature pelicans die each year in Florida alone from entanglement in sport-fishing gear.
*While the Brown Pelican is draining the water from its bill after a dive, sea gulls often try to steal the fish right out of its pouch.
*Pelicans incubate their eggs with the skin of their feet, essentially standing on the eggs to keep them warm. In the mid-twentieth century the pesticide DDT caused pelicans to lay thinner eggs that cracked under the weight of incubating parents. After nearly disappearing from North America in the 1960s and 1970s, Brown Pelicans made a full comeback thanks to pesticide regulations.
*During a dive, the Brown Pelican tucks its head and rotates its body to the left. This maneuver is probably to cushion the trachea and esophagus—which are found on the right side of the neck—from the impact.
*The oldest Brown Pelican on record was 43 years old.
*Brown Pelicans live year-round in estuaries and coastal marine habitats along both the east and west coasts. On the Atlantic and Gulf coasts they breed mostly on barrier islands, natural islands in estuaries, and islands made of refuse from dredging, but in Florida and southern Louisiana they primarily use mangrove islets.
*Brown Pelicans mostly eat small fish that form schools near the surface of the water—including menhaden, mullet, anchovies, herring, and sailfin mollies.