The Barnacle goose (Branta leucopsis) is a species of goose that belongs to the genus Branta of black geese. Despite its superficial similarity to the Brant goose, genetic analysis has shown it is an eastern derivative of the Vackling goose lineage.
The Barnacle goose has a white face and black head, neck, and upper breast. Its belly is white. The wings and its back are silver-gray with black-and-white bars that look like they are shining when the light reflects on them. During the flight, a V-shaped white rump patch and the silver-gray underwing linings are visible.
Barnacle geese occur in three main populations, with separate breeding and wintering ranges, from west to east which include eastern Greenland, Svalbard, and Novaya Zemlya (northern Russia and the extreme northeast of Europe). A new fourth population, derived from the Novaya Zemlya population, has been established since 1975 and breeds on the islands and coasts of the Baltic Sea (Estonia, Finland, Denmark, and Sweden). Occasionally, wild birds will appear in the Northeastern United States or Canada. Barnacle geese breed in coastal tundra with cliffs, rocky outcrops, and steep slopes, often near lakes, rivers, and marshes. On the wintering grounds, they prefer grassy fields near the coastal regions, mudflats, and salt marshes.
Barnacle geese are gregarious birds; they nest, feed, and migrate in large flocks. They are active during the day spending most of the time foraging above-ground. Barnacle geese molt after nesting; during this time they can't fly and stay in protected areas such as lakes or at sea in order to avoid predators. After the molting period, birds usually congregate at the gathering sites, where they feed before the migration to their wintering grounds.
Barnacle geese are herbivorous (folivorous, graminivorous) birds. They feed mainly on leaves, herbs, grass, roots, mosses, sedges, and aquatic vegetation. During the winter they may feed on agricultural grain and occasionally vegetables.
Barnacle geese are monogamous and form long-lasting pair bonds. They breed in late May-June usually in colonies that may include up to 50 pairs. Females construct the nests locating them on cliff edges in order to avoid predators. The nest is made of dead foliage and mud and lined with down. The female lays 3 to 5 white eggs, and incubates them for 24-26 days; during this time the male feed and protects her. At hatching, goslings are precocial (well-developed); they are able to leave the nest soon after birth and follow their parents to nearby marshes to feed themselves. The young fledge at 40 to 45 days old and become reproductively mature when they are 2-3 years old.
Barnacle geese are persecuted by farmers because during the winter they often visit fields and farmlands to feed on grass. In Svalbard, these birds also suffer from predation by Arctic foxes which hunt adult birds, eggs, and newly hatched goslings.
According to the IUCN Red List, the total population size of the Barnacle goose is around 880,000 individuals. The European population consists of 196,000-247,000 pairs, which equates to 392,000-494,000 mature individuals. According to the Wikipedia resource, the species population numbers have been estimated in such areas: Greenland - about 40,000 individuals; Svalbard - about 24,000 individuals; Novaya Zemlya (Russia) - about 130,000 individuals; on the islands and coasts of the Baltic Sea (Estonia, Finland, Denmark, and Sweden) - about 8,000 individuals. Overall, currently, Barnacle geese are classified as Least Concern (LC) on the IUCN Red List and their numbers today are increasing.
Barnacle geese are important seed dispersers in their ecosystem as they feed on a wide variety of herbs and grasses. These birds are also a food source for local predators such as falcons, polar bears, and Arctic foxes.
