The Atlantic Puffin is sturdily built with a thick-set neck and short wings and tail. It is 28 to 30 centimetres (11 to 12 in) in length from the tip of its stout bill to its blunt-ended tail. Its wingspan is 47 to 63 centimetres (19 to 25 in) and on land it stands about 20 cm (8 in) high. The male is generally slightly larger than the female, but they are coloured alike. The forehead, crown and nape are glossy black, as are the back, wings and tail. A broad black collar extends around the neck and throat. On each side of the head is a large, lozenge-shaped area of very pale grey. These face patches taper to a point and nearly meet at the back of the neck. The shape of the head creates a crease extending from the eye to the hindmost point of each patch giving the appearance of a grey streak. The eye looks almost triangular in shape because of a small, peaked area of horny blue-grey skin above it and a rectangular patch below. The irises are brown or very dark blue and each has red orbital ring. The underparts of the bird, the breast, belly and undertail coverts, are white. By the end of the breeding season, the black plumage may have lost its shine or even taken on a slightly brownish tinge. The legs are short and set well back on the body giving the bird its upright stance on land. Both legs and large webbed feet are bright orange, contrasting with the sharp black claws. The beak is very distinctive. From the side the beak is broad and triangular but viewed from above it is narrow. The half nearest the tip is orange-red and the half nearest to the head is slate grey. There is a yellow chevron-shaped ridge separating the two parts and a yellow, fleshy strip at the base of the bill. At the joint of the two mandibles there is a yellow, wrinkled rosette.
Habitat and Distribution
The Atlantic Puffin is a bird of the colder waters of the North Atlantic Ocean. It breeds on the coasts of north west Europe, the Arctic fringes and eastern North America. While at sea, the bird ranges widely across the North Atlantic Ocean, including the North Sea, and may enter the Arctic Circle. In the summer, its southern limit stretches from northern France to Maine and in the winter the bird may range as far south as the Mediterranean Sea and North Carolina.
The Atlantic Puffin diet consists almost entirely of fish, though examination of its stomach contents shows that it occasionally eats shrimps, other crustaceans, molluscs and polychaete worms, especially in more coastal waters. When fishing, it swims underwater using its semi-extended wings as paddles to `fly` through the water and its feet as a rudder. It swims fast and can reach considerable depths and stay submerged for up to a minute. It can eat shallow-bodied fish as long as 18 cm (7 in) but its prey is commonly smaller fish, around 7 cm (3 in) long. It has been estimated that an adult bird needs to eat about forty of these per day?sand eels, herring, sprats and capelin being the most often consumed. It fishes by sight and can swallow small fish while submerged, but larger specimens are brought to the surface. It can catch several small fish in one dive, holding the first ones in place in its beak with its muscular, grooved tongue while it catches others. The two mandibles are hinged in such a way that they can be held parallel to hold a row of fish in place and these are also retained by inward-facing serrations on the edges of the beak. It copes with the excess salt that it swallows partly through its kidneys and partly by excretion through specialised salt glands in its nostrils
Egg-laying starts in April in more southerly colonies but seldom occurs before June in Greenland. The female lays a single white egg each year but if this is lost early in the breeding season, another might be produced. Synchronous laying of eggs is found in Atlantic Puffins in adjacent burrows. The egg is large compared to the size of the bird, averaging 61 millimetres (2.4 in) long by 42 millimetres (1.7 in) wide and weighing about 62 grams (2.2 oz). The white shell is usually devoid of markings but soon becomes soiled with mud. The incubation responsibilities are shared by both parents. They each have two feather-free brood patches on their undersides where an enhanced blood supply provides heat for the egg. The parent on incubation duty in the dark nest chamber spends much of its time asleep with its head tucked under its wing, occasionally emerging from the tunnel to flap dust out of its feathers or take a short flight down to the sea. Total incubation time is around 39-45 days. From above ground level, the first evidence that hatching has taken place is the arrival of an adult with a beak-load of fish. For the first few days the chick may be fed with these beak-to-beak but later the fish are simply dropped on the floor of the nest beside the chick which swallows them whole.