|
|
|||||||||||
|
|
|||||||||||
 |
 |
||||||||||
|
|||||||||||
Background 
"To see a gull beating high over our meadowy flood…is akin to seeing a mackerel schooner on the coast. It is the nearest approach to sailing vessels in our scenery." Henry David Thoreau, Journals. BackgroundGulls belong to the large family of shorebirds, containing 51 species, known as Laridae, and can be found nesting, hovering and flying along shorelines around the world, except in some tropical areas. Although a common sight in coastal areas, gulls are complex animals that exhibit, worldwide, an interesting range of behaviors and life-cycle changes. Some species take nearly four years to reach maturity and undergo at least nine plumages, molting twice a year, including a brief juvenile plumage. Most species migrate to some extent. These are gregarious and not particularly territorial animals; they may share nesting grounds with members of other species. Four species of gull are common to the Chesapeake Bay and its environs, in addition to some seasonal visitors. The laughing gull, ring-billed gull, great black-backed gull and herring gull thrive throughout the Bay area. Sometimes the ternlike Bonaparte's gull, which resembles the laughing gull (though smaller) in its hooded summer plumage, can be found wintering in small groups. Gulls in the Chesapeake Bay region are typically found close to land, near bulkheads and wharves. They use warm thermals from heated pavements to keep them aloft without having to exert extra energy, while they hunt for bits of food, and often use gravity and those pavements as "tools" to crack open the tough shells of their prey. Laughing gullLarus atricilla has a call that resembles human laughter, and is the smallest of the four species that are common to the Bay. It is the most abundant species during the summer months. The laughing gull can be seen in rural areas, following behind farmers as they plow, searching for grubs of insects that emerge with the clumps of tilled soil. It achieves breeding plumage after three years (making it a "three-year gull")-a black hood and white underbelly, with pale gray wings and back. Its bill is dark red, and it has black feet and legs. In winter it loses the black coloration around the head but retains its gray plumage. Ring-billed gullLarus delawarensis is also a three-year gull, one that shares the laughing gull's passion for grubs in freshly-plowed fields, and the most abundant winter gull in the Chesapeake Bay. Its adult breeding plumage shows a typically gray mantle, white head and underbelly, and a black ring near the tip of its yellow bill. It is sometimes taken for a herring gull because of its color and similar call, but its smaller size and black ring during the breeding phase sets it apart. Ring-bills are, like many gulls, voracious feeders, consuming everything from fish and small mammals to bird eggs, insects or refuse. Great black-backed gull Larus marinus is distinguished by its massive yellow bill and broad wingspan, which sometimes reaches five feet. This impressive bird takes four years to reach maturity. During its breeding phase it has charcoal black upper wings, with white underbelly and pink legs. Its call is deeper than a herring gull's. Its chicks peck at the red spot on its lower bill to request food. Like its cousin the herring gull, the great black-backed gull will drop mollusks to the ground while hovering above in order to crack them open. They consume shellfish such as clams and oysters, as well as the eggs and chicks of other birds. Herring gullLarus argentatus is also a four-year gull, and nearly as large as the black-backed gull. As a breeding adult it has a white head and pale gray mantle, with yellow bill and a red spot under its bill. The herring gull's chicks may also peck at the red spot to stimulate the adult's feeding behavior. This may be the most familiar gull along the entire Atlantic coastline, and it is a familiar sight, gathered in great masses, at landfills and garbage dumps. The herring gull consumes eggs and chicks of other birds, insects, fish, mollusks, and refuse. It lays about three greenish-blue eggs during nesting, which hatch within 28 days.
To bookmark this page, please use this URL: http://www.chesapeakebay.net/laridae.htm For more information, contact the Chesapeake
Bay Program Office: Terms
of Use | Privacy Policy
| Contact Us |
|||||||||||
 |
 |
||||||||||
