Sanderling (Calidris alba)

The sanderling is a circumpolar breeder in high arctic regions in Alaska, arctic Canada, north and east Greenland, Svalbard and western and central Siberia. The sandlerling is a small wading bird that is often seen running rapidly in the tidal zone. They are migratory, wintering along the coast southwards to South America, South Africa and Australia. Considerable numbers pass along the coast of Norway during their migrations in the spring and autumn.

The sandlerling is a small wading bird that is often seen running rapidly in the tidal zone. The sexes are similar in appearance. In summer the plumage of the head, upper-parts of the body and the breast are a rusty-brown with darker patches and lines. The breast is sharply delimited against the white belly. In flight a white wing bar can be seen clearly. The bill and legs are black. Sanderlings usually have winter plumage from September onwards, which is much whiter than the other waders. The upper-parts of the body are light grey with dark shoulder marks, while the inside of the wings and the whole belly is white. Juveniles have light grey-black upper-parts with white and yellow-brown tipped feathers. The underside is white with yellow-brown lines along the side of the breast. Like the adults, it has a distinct, white wing bar. The call is a sharp "quit-quit".

Distribution

The sanderling is a circumpolar breeder in high arctic regions in Alaska, arctic Canada, north and east Greenland, Svalbard and western and central Siberia. They are migratory, wintering along the coast southwards to South America, South Africa and Australia. Considerable numbers pass along the coast of Norway during their migrations in the spring and autumn. In Svalbard the sanderling is a rare breeder in the western and north-western parts of Spitsbergen, including Prins Karls Forland. It appears in small flocks on tidal flats along the coast and in river deltas in the first part of June, before spreading out into breeding areas on the tundra. Most of the birds probably leave the archipelago in August; juvenile birds are thought to leave somewhat later (September).

Ecology

Sanderlings occur in the breeding season on stony, dry parts of the tundra, in areas with sparse vegetation. The breeding area is usually not far from fresh water. Outside the breeding season sanderlings can be found on mudflats and sandy shores along coastlines and in some places near fresh water; they often occur in large flocks outside the breeding season. They feed on small invertebrates both in the intertidal zone and on the tundra. They also eat plant material, particularly early in the breeding season when animal prey is not available. Sanderlings feed by probing.

Life history and reproduction

The sanderling is a solitary breeder. Their nest is a shallow scrape in the vegetation or on bare ground; it is usually lined with grass or leaves. The nest is built by the female, and often placed on a slightly raised area. Egg laying starts in the middle of June or thereafter, depending on the timing of snow melt. The four pear-shaped eggs are olive-green with brown speckles and are incubated for 23–24 days. In Canada it has been shown that sanderling pairs can have two nests with one clutch of eggs in each, with the male and female each incubating and rearing a brood. This breeding strategy could compensate to some extent for the predation of eggs and young in seasons when reproduction is low due to a late snow melt or other unfavourable weather conditions. In Greenland however, investigations have shown that the species has only one clutch and that both sexes take part in incubation. The situation in Svalbard is unknown. The young are cared for by one or both parents and are fledged after about 17 days. The highest age recorded in Norway (including Svalbard) is 17 years.

Management status and monitoring

The breeding population is thought to be very small in Svalbard (perhaps 20 to 100 pairs). However, no reliable census of the population has been conducted, and there is no monitoring of population trends. The European population is estimated to be some 50,000 pairs, and is considered stable.

MOSJ indicators (Environmental Monitoring of Svalbard and Jan Mayen):

Awaiting results from MOSJ…