The Brant is a small species of goose belonging to the genus Branta. This marine bird is distinctly smaller than other familiar geese, like the Canada Goose, and prefers coastal environments. It has a short neck and compact body structure. Unlike most other geese that utilize inland fields for foraging, the Brant rarely strays far from saltwater habitats.
Physical Characteristics and Identification
The Brant typically measures between 55 and 66 centimeters in length with a wingspan of 106 to 121 centimeters. Its compact size and short, stubby bill give it a unique appearance among waterfowl. The adult bird features a striking black head, neck, and chest, contrasting with the rest of its plumage. A defining feature is the small, partial white patch or collar located on either side of the neck.
Subtle variations in belly coloration define the three major subspecies.
Subspecies Differences
The Pale-bellied Brant (Atlantic Brant) possesses a lighter gray belly that sharply contrasts with its black chest. Conversely, the Dark-bellied Brant has a more uniformly dark gray-brown body, showing less contrast between the flanks and back. The Black Brant, a Pacific subspecies, is the darkest of the three, displaying a dark gray belly and a more conspicuous white neck patch, sometimes forming a near-complete collar. All subspecies share a pure white undertail, which is noticeable when the birds are resting on the water.
Geographic Range and Migration
Brant undertake long migratory journeys, connecting their remote Arctic breeding grounds to temperate coastal wintering areas. They breed farther north than any other goose, nesting on the high-Arctic tundra across North America, Europe, and Asia. These breeding sites are typically low-lying, wet coastal areas.
The subspecies follow distinct flyways to reach strictly coastal wintering destinations, such as estuaries, bays, and sheltered shorelines. For example, the Pale-bellied Brant migrates down the Atlantic coast of the United States, while the Black Brant travels down the Pacific coast from Alaska to Baja California. Some populations undertake non-stop flights over open water, traveling over 3,000 miles annually.
Brant often linger later in the spring than other migratory geese because the high Arctic breeding grounds remain unsuitable for nesting until the summer thaw. They are rarely sighted inland due to their strict reliance on coastal habitats.
Unique Feeding Habits
The Brant possesses highly specialized feeding habits that tie it directly to marine ecosystems, unlike many grazing geese. Its diet is dominated by aquatic vegetation, particularly the submerged marine flowering plant known as eelgrass (Zostera marina). During the wintering season, eelgrass can constitute up to 80 percent of a Brant’s diet.
This dependency makes the Brant vulnerable to habitat changes. For instance, a disease in the 1930s severely reduced eelgrass beds, causing a significant drop in the Brant population. Surviving birds, especially the Atlantic Brant, adapted by consuming supplementary food sources, such as sea lettuce and salt marsh plants. Brant typically forage by grazing, either by walking on exposed tidal flats at low tide or by tipping forward in shallow water to reach the vegetation.