Breeding birds: 900 pairs
Wintering birds: 94,000
Family: Ducks, geese & swans
Adult barnacle geese have grey and black barred upperparts. The side of the rump and the uppertail coverts are white and the rounded tail is black. The flight feathers of the upperwing are black with an inner grey web, the scapulars are pale grey, and the wing coverts are grey with black and white tips.
The underparts are much paler with slight pale grey bars on the flanks. The underwing coverts are pale grey, and the undertail coverts are white.
The head is white or pale buff with a black crown and nape. The short bill is black, the eyes are dark brown with a small eye patch, and the legs and webbed feet are black. Males and females look similar except the male is slightly larger.
Juvenile barnacle geese are duller with a grey neck and the white parts of the head have grey flecks. They have a brown tinge to the upperparts and the flanks are washed with pale buff. They reach full size when they are two years old.
Barnacle goose breed in late May and June and produce 1 brood a season. They are monogamous and form life-long pair bonds. They breed in colonies of up to 50 pairs as well as solitary pairs. The female builds the nest, which is in a shallow depression in the ground and made from mud and dead leaves, lined with grass, moss and down. They will also nest on the edges of cliffs to try and avoid predators.
Barnacle geese lay 3-6 white, pale grey, or pale yellow eggs which are incubated by the female for 24-28 days while the male guards the nest. Chicks have grey down on their upperparts and white down on their underparts. They are precocial and leave the nest soon after hatching and can feed themselves. They are fully independent at 40-45 days and reach sexual maturity at 2-3 years.
If the nest has been built on a cliff edge then the chicks must jump to the ground as they are unable to fly. This often causes injury or even death although a good number do survive.
Barnacle geese eat grass, stems, leaves and aquatic vegetation. They will also venture onto farmland to eat crops.
Barnacle geese can be seen between October and March. The best place to spot them is on the Solway Firth in Scotland and England.
A medieval legend said that the barnacle goose was born from driftwood because it was not seen in the summer when it was supposedly developing under the water.