One of the most cherished sights along the North Carolina coast is a skein of brown pelicans soaring effortlessly over the sea, often flying so low that their wingtips trace lines in the water surface. With its four-foot wingspan and extraordinary bill, the bird is quite ungainly when it waddles about on land. But once aloft, it inspires dreams of flight among we earthlings.
Brown pelicans nest in large coastal colonies from Maryland, south along the Florida peninsula, the Gulf of Mexico, the Gulf of California and north along the Pacific Coast to the San Francisco Bay.
White pelicans, on the other hand, nest inland on freshwater from the northwestern states and upper Midwest well into the Canadian Provinces of Saskatchewan, Alberta and British Columbia.
At an average weight of 16 pounds, the white pelican is twice the size of the brown pelican. It has a wingspan of nine feet and a foot-long bill.
Both species were brought to the brink of extinction by DDT which was so widely used in the mid-1900s. This chemical that targeted agricultural pests progressed up through the food chain, ultimately causing thinning of eggshells of pelicans, bald eagles and peregrine falcons, among others. Concentration of DDT in their prey caused shells to be so thin that the eggs broke during incubation, resulting in the failure to reproduce among these birds.
Since DDT was banned in 1974, it has largely dissipated from the environment and populations of these birds have rebounded.
Though the two pelican species feed on small fish that they scoop up in their expandable dip-net-like throat pouches, their feeding techniques are quite different.
Brown pelicans are plunge-divers. They glide over the waters looking below for schools of fish. When they find them, they pull up to stall the glide, draw their wings back while pointing their bills downward and plunge into the water.
This sudden impact from above stuns some fish and disorients others long enough for the bird’s bill to corral them. The flexible lower mandible and throat expand to a capacity of over two and a half gallons and the upper mandible keeps any fish from escaping.
On a successful dive, the bird sits on the surface of the water and tilts the bill downward, allowing the water to drain before lifting the head and swallowing the prey. Unlike many fish-eating birds, pelicans don’t kill their prey before downing it, but swallow it live.
Brown pelicans sometimes gather at large schools of fish and several may be seen diving, then rising in the air to dive again. But their feeding actions are not coordinated; it’s each bird for itself.
White pelicans congregate in groups and cooperate to catch food. A group will form a semicircle and drive schools of fish toward the shore by dipping their bills in the water in a synchronized fashion while beating their wings on the surface.
As the prey are driven to shallower water, they are more easily caught.
Brown pelicans abound all along the N.C. coast. Small numbers of white pelicans can often be seen in winter in the impoundments at Pea Island National Wildlife Refuge south of Nags Head.
Anyone with an interest in nature will find these extraordinary birds and many others worthy of a winter trip to the Outer Banks.