Brant

Branta bernicla

(c) Glen Tepke
  • ANATIDAE
  • Swans, Geese, Ducks
  • Anseriformes
  • Barnacla carinegra
  • Bernache cravant
Introduction
In loose V's and U's, flocks of Brant range North American coasts in search of eelgrass and other marine plants. This small, dark sea goose breeds in the far north, and its long migrations to and from the high arctic require powerful, swift flight.
(c) Howard Eskin
Appearance Description
Smaller than a Canada Goose, but larger than a Mallard, the Brant has a black head and neck with a white throat patch. The short neck, smallish head, and small bill give this bird a delicate appearance. Eastern populations tend to have a grayish belly and chocolate brown mantle. In western populations, these areas are much darker, or even black. The lower body is white from the legs to the tail, which has a black tip. Brant reach 25 inches in length and weigh about three pounds, with a 42-inch wingspan.
Range Distribution
Usually near coastal areas, Brant breed from the low to the high arctic, ranging irregularly from western Alaska to the far north of Hudson Bay. During winter, two subspecies are seen in North America: the Light-bellied Brant ranges from coastal Massachusetts to North Carolina, and the Black Brant winters at a few sites from the southern Alaskan coast into the Gulf of California.
 
A legend for the range map to the right can be found here.
Habitat
Brant breed on flat or gently sloping arctic tundra areas. Near coasts and salt marshes, plants like alkali grass and Hoppner's sedge provide the birds' only cover. Migrating and wintering Brant prefer shallow, coastal waters rich in marine plants. Adjacent grasslands are used reluctantly in response to severe freezing conditions.
Feeding
Dipping, dabbling, and pecking, flocks of non-breeding Brant forage on marine plants. Breeding Brant rely on high-protein grasses like Hoppner's sedge, tufted hairgrass, marsh arrowgrass, and pondweed. Migrating and wintering Brant consume green algae, sea lettuce, and eelgrass, which was a larger component of this goose's diet before vast intertidal fields were destroyed by disease. Although a large salt gland allows Brant to drink salt water, this sea goose prefers fresh water.
Reproduction
Like most geese, Brant mate for life, maintain family groups into the spring, and breed in colonies. Pairs form before arriving on the breeding grounds. Males sometimes defend territories, but often nests are less than a few yards apart and situated on small islands in ponds or gravel bars between running water. In early June, the female forms a depression in the soft tundra and tosses in grasses, leaves, and other plant parts before laying three to five whitish eggs. In the high arctic climate, down is an important component of the nest, and Brant deposit as much down as any other duck or goose, including eiders. This down sticks to itself and the nest, so as not to blow away.
 

 

While the male Brant provides defense, the female incubates the eggs for about three weeks and, upon hatching, broods her chicks for another week or two. Within a day, hatchlings can walk, feed, and hide on their own. Both parents attend to the chicks, leading them to foraging areas, and accompanying them during migration when the juveniles fledge, about six weeks after hatching.
Migration
Breeding in the high arctic and wintering into the Gulf of California, loose flocks of Brant may migrate more than 5,500 miles. Almost all migrants stage and refuel at either Izembek Lagoon on the Alaska Peninsula or James Bay, Canada. In late October, some southbound Brant do not stop at all during the 2,700-mile journey between Izembek and the Gulf of California, covering the distance in as little as 54 hours.
  • 544,400
  • 319,400
Population Status Trends
Brant populations have experienced significant changes in the last century. In the 1930s, Brant numbers in North America and Europe fell when winter food supplies crashed. Severe winters in the mid-1970s contributed to the loss of half of the eastern population; partial recovery had occurred by the early 1990s. Pacific Brant populations have exhibited similar fluctuations. Although recent Christmas Bird Counts have recorded more Brant on both coasts, over-hunting, extreme coastal weather, habitat loss, and declining food sources have kept Brant populations chronically low. The U. S. Fish and Wildlife Service designates the Brant as a "Bird of Management Concern."
 
Conservation Issues
Brant have suffered from over-hunting, diminished food supplies, and severe oceanic conditions, recently linked to El Niño/La Niña weather patterns. Coastal land development and commercial shellfishing also threaten the marine wetlands where Brant graze. Along the Pacific Coast, dredged materials and piles of wasted shells, both resulting from oyster processing, ruin beds of eelgrass, a primary food source for Brant. Eelgrass, like other saltwater "grasses," is susceptible to erosion, smothering by sedimentation, overly high nutrient levels, and disease caused by freshwater run-off.
 

The Izembek Lagoon on the Alaska Peninsula, a key staging areas for Brant migration, is currently threatened by oil and gas exploration. Bristol Bay, immediately adjacent to the Izembek National Wildlife Refuge, has been excluded from offshore drilling since 1989. However, Congress lifted the drilling moratorium in November 2003, and the Minerals Management Service is now considering Bristol Bay in its five-year Offshore Oil and Gas Lease Sale Program (2007-2012). During both spring and fall migrations, almost all Brant in the Pacific Flyway stop at Izembek and fly over Bristol Bay. Foraging sites are especially important for juvenile Brant during fall migration, a period of high mortality. An oil spill, coupled with a year of bad weather or mismanaged hunting, could be devastating for migrating Brant.

What You Can Do
Enjoy Brant as they migrate and winter on the Atlantic and Pacific coasts. Check with a local bird club for trips in search of wintering waterfowl.
 
Support bird festivals and events that focus attention on key waterbird habitats and raise funds for protecting, conserving, and rehabilitating coastal wetlands. Visit California's Morro Bay Winter Bird Festival from January12 to 15, 2007, and Washington's Wings Over Water Pacific Northwest Birding Festival.
 
Support the moratorium on offshore drilling in Bristol Bay and the President's withdrawal of this area from the proposed Offshore Oil and Gas Lease Sale Program. Learn more about this proposal at the Alaska Marine Conservation Council and read the draft proposal by the U. S. Department of the Interior's Minerals Management Service.
 
Purchase Federal Duck Stamps, which provide for the protection and research of Brant.
 
For more actions you can take, including Audubon activities, please visit our resources page.
More Information
Visit our resources page for more information about this species.
Natural History References
"Common Eelgrass (Zostera marina)" Species and Habitats. The Marine Life Information Network (The Marine Biological Association). 6 December 2006.
 
Ganter, B. "Seagrass (Zostera spp.) as food for brant geese (Branta bernicla): An Overview." Helgoland Marine Research 54:2-3 (July 2000) 63-70.
 
Kaufman, Kenn. Lives of North American Birds. Houghton Mifflin Company, New York, 1996.

 

 
Reed, A., D. H. Ward, D. V. Derksen, and J. S. Sedinger. 1998. Brant (Branta bernicla). In The Birds of North America, No. 337 (A. Poole and F. Gill, Eds.). The Birds of North America, Inc., Philadelphia, PA.
 
Sedinger, James S., et al., "Effects of El Niño on distribution and reproductive performance of black brant." Ecology 87:1 (June 2005) 151-159.
 
Sibley, David Allen. The Sibley Guide to Birds. Alfred A. Knopf, New York. 2000.
 
Ward, David H. et al. "Temporal and geographic variation in survival of juvenile Black Brant." The Condor 106:2 (May 2004) 263-274.
Conservation Status References
"Common Eelgrass (Zostera marina)" Species and Habitats. The Marine Life Information Network (The Marine Biological Association). December 6, 2006.
 
Ganter, B. "Seagrass (Zostera spp.) as food for brant geese (Branta bernicla): An Overview." Helgoland Marine Research 54:2-3 (July 2000) 63-70.
 
Kaufman, Kenn. Lives of North American Birds. Houghton Mifflin Company, New York, 1996.

 

 
Reed, A., D. H. Ward, D. V. Derksen, and J. S. Sedinger. 1998. Brant (Branta bernicla). In The Birds of North America, No. 337 (A. Poole and F. Gill, Eds.). The Birds of North America, Inc., Philadelphia, PA.
 
Sedinger, James S., et al., "Effects of El Niño on distribution and reproductive performance of black brant." Ecology 87:1 (June 2005) 151-159.
 
Sibley, David Allen. The Sibley Guide to Birds. Alfred A. Knopf, New York. 2000.
 
Ward, David H. et al. "Temporal and geographic variation in survival of juvenile Black Brant." The Condor 106:2 (May 2004) 263-274.