The dunlin is a small wader, which is more slender than the purple sandpiper. It breeds in a circumpolar range in Arctic and several north temperate regions. The dunlin is one of the most abundant wader species in the world. In Svalbard the dunlin has been reported breeding in small numbers on Bjørnøya and in the western parts of Spitsbergen, mainly in the Isfjorden and Kongsfjorden areas.
The dunlin is a small wader, which is more slender than the purple sandpiper. The sexes have a similar appearance. Adult birds are about 18 cm long and weight 40–65 g.
The summer plumage is brown-black on the back with rusty-brown and yellow-brown feather tips; the neck and breast are brown-streaked. Dunlins have a distinctive large black triangular-shaped patch which covers the front of the chest and belly. The bill is dark and often slightly curved at the tip. The legs are black. The winter plumage, which comes during September, is light grey-brown on the upper-parts, white on the under-parts and grey streaked on the breast. A faint wing bar can be seen when the bird is in flight. Dunlins are distinguished in winter plumage from the curlew sandpiper by a dark central stripe on the upper part of the rump.
Juveniles resemble the adults in summer plumage, but are dark brown on their upper-parts with yellow-brown edged feathers; they have a speckled yellow-brown breast and a white belly with dark speckles on the flanks.
The voice is a grating ‘creep’; when in flight dunlins emit a warbling ‘cree-ree-ree-ree’ call. During the breeding season the dunlin can often be located by the warbling sounds it emits during display flights.
The dunlin breeds in a circumpolar range in arctic and north temperate regions in Alaska, northeast Canada, east Greenland, Iceland, the British Isles, through north-west Europe, Svalbard and Siberia. The species is divided into several subspecies which are geographically isolated. Dunlins in Svalbard belong to the C. a. alpine subspecies, which also breeds in northern Scandinavia and the north-western parts of Russia.
The dunlin is one of the most abundant wader species in the world. In Svalbard the dunlin has been reported breeding in small numbers on Bjørnøya and in the western parts of Spitsbergen, mainly in the Isfjorden and Kongsfjorden areas. It might have a wider breeding distribution than is presently known, but the dunlin is not an abundant wader in Svalbard. The birds that breed in Europe spend winter from the coast of western Europe in the north down to the Mediterranean and as far south as north-west Africa.
The dunlin breeds and feeds in marshlands, but can also be seen in intertidal areas, where it is often together with other species of waders. It often occurs in large flocks of up to 50 individuals. Dunlins arrive in Svalbard toward the end of May or early June. They migrate southwards at the end of July through to the middle of August. Their diet consists of insects and other invertebrates which are found in wet tundra areas and in the intertidal zone.
Life history and reproduction
Dunlins breed in solitary pairs or loose groups and are territorial on the breeding grounds. The nest is placed in flat, moist terrain near ponds and lakes, usually in concealing vegetation such as a grass tussock. The nest is bowl-shaped and is lined with straw and willow leaves.
The four pear-shaped eggs are buff or olive-brown with chestnut-brown speckles and blotches. The eggs are incubated by both sexes for 22 days.
The dunlin is monogamous and the same pair often breeds in the same locality in successive years.
The young leave the nest immediately after hatching and are protected by the parents, but the female usually leaves the family before the young are fledged at about three weeks of age. Dunlins are sexually mature when they are one to two years old.
The highest age recorded in Norway (including Svalbard) is 24 years.
Management status and monitoring
The size of the dunlin breeding population in Svalbard is not known, and no surveys or censuses have been conducted. However, it is reasonable to believe that the breeding population is less than fifty pairs. The European breeding population is estimated to be somewhat in excess of 300,000 pairs. The west-European population has been stable during recent decades, whereas the east-European (Baltic and Russia) population has been declining.