A brant, photographed while swimming in coastal waters. Courtesy: E. Marks, Audubon Society of Rhode Island

Brant (Branta bernicla)

Field markings: 25 inches long. Dark colored with a black head, neck, and breast. White patch on both sides of the neck, just under the throat. Underside of the body is gray, lightening to white at the tail, with a black bar at its end. Juveniles lack the white neck pattern.
Habitat: Saltwater inlets and estuaries.
Seasonal appearance: Winter, early spring.

Description

The brant is a small, dark, sea goose, slightly larger than a mallard duck. The genus name Branta is derived from the German word "brand" meaning burnt, referring to its dark feathers, and the species name bernicla is from the Norwegian word for barnacle. An ancient legend associated with the brant is that they hatch from barnacles on driftwood.

Life History and Behavior

Brant fly with rapid wing beats on long and pointed wings. Flocks of brant fly low in a ragged formation. The flocks do not form in a "V" shape as some geese do; instead they bunch together or form long wavy lines. Brant travel along the coast and are usually found on sandy peninsulas and bars. They generally avoid migrating over land.

Brant return to the same nesting site year after year as many birds instinctively do. They are monogamous, forming lifelong pair bonds at three years of age. The main food sources for brant geese are eelgrass, aquatic plants, moss, lichen, crustaceans, mollusks, worms, insects, and some grain. They feed in a manner similar to ducks, dipping from the water's surface and dabbling in the submerged vegetation. When feeding, they have sentinel guards watching for possible predators.

To survive in a strictly saltwater environment, brant have salt glands located at the base of the bill to filter excess salt from the blood stream, concentrate it, and excrete it through the bill. This allows the birds to drink seawater and eat saltwater vegetation without becoming dehydrated.

Special Notes

• Brant are dependent on eelgrass, which provides 80 percent of their winter diet. Recent brant population declines in Narragansett Bay have been attributed to a decline in Bay eelgrass.
• The Atlantic brant population was decimated in the 1930s and 1940s when eelgrass beds were killed by disease.
• The population has not returned to its former numbers even though some brant have adapted to eating sea lettuce and other vegetation.

Adapted from The Uncommon Guide to Common Life on Narragansett Bay. Save The Bay, 1998.