Regular passage visitor and winter visitor.
While many North Americans know this medium-sized (8-9 inches) sandpiper as a plain, gray bird of the winter shoreline, the Dunlin has a summer plumage which is much more striking. During the breeding season, this sandpiper is rusty-red speckled with brown above with a white eye-stripe, long black bill, black legs, and black breast patch. In winter, this species sheds its summer colors and becomes gray above with a white breast and gray throat. Male and female Dunlins are similar in summer and winter plumages. The Dunlin breeds across arctic and subarctic regions of the Northern Hemisphere. In North America, this species breeds primarily along northwestern portions of the Hudson Bay, with smaller populations breeding in Alaska and the islands in the Canadian arctic. Most Dunlin breeding in North America winter along both coasts of the continent south to central Mexico. In the Old World, this species breeds across northern Russia, Northern Europe, and Iceland, wintering as far south as the Mediterranean Sea, West Africa, South Asia, and the Oceania. In summer, Dunlins breed on relatively wet, boggy tundra. During the winter, this species primarily inhabits shorelines of sandy beaches, although some birds winter on agricultural land in California’s Central Valley. The diet of the Dunlin is comprised mostly of small aquatic invertebrates such as crustaceans and mollusks, although insects may also be eaten when available. Due to its remote breeding habitat, most birdwatchers never see the Dunlin during the summer. In winter, this species may be observed in groups probing the sand for food with their bills and running to avoid incoming waves. Dunlins are primarily active during the day.
While many North Americans know this medium-sized (8-9 inches) sandpiper as a plain, gray bird of the winter shoreline, the Dunlin has a summer plumage which is much more striking. During the breeding season, this sandpiper is rusty-red speckled with brown above with a white eye-stripe, long black bill, black legs, and black breast patch. In winter, this species sheds its summer colors and becomes gray above with a white breast and gray throat. Male and female Dunlins are similar in summer and winter plumages. The Dunlin breeds across arctic and subarctic regions of the Northern Hemisphere. In North America, this species breeds primarily along northwestern portions of the Hudson Bay, with smaller populations breeding in Alaska and the islands in the Canadian arctic. Most Dunlin breeding in North America winter along both coasts of the continent south to central Mexico. In the Old World, this species breeds across northern Russia, Northern Europe, and Iceland, wintering as far south as the Mediterranean Sea, West Africa, South Asia, and the Oceania. In summer, Dunlins breed on relatively wet, boggy tundra. During the winter, this species primarily inhabits shorelines of sandy beaches, although some birds winter on agricultural land in California’s Central Valley. The diet of the Dunlin is comprised mostly of small aquatic invertebrates such as crustaceans and mollusks, although insects may also be eaten when available. Due to its remote breeding habitat, most birdwatchers never see the Dunlin during the summer. In winter, this species may be observed in groups probing the sand for food with their bills and running to avoid incoming waves. Dunlins are primarily active during the day.
The dunlin (Calidris alpina) is a small wader, formerly sometimes separated with the other "stints" in the genus Erolia. The English name is a dialect form of "dunling", first recorded in 1531–1532. It derives from dun, "dull brown", with the suffix -ling, meaning a person or thing with the given quality.[2]
It is a circumpolar breeder in Arctic or subarctic regions. Birds that breed in northern Europe and Asia are long-distance migrants, wintering south to Africa, southeast Asia and the Middle East. Birds that breed in Alaska and the Canadian Arctic migrate short distances to the Pacific and Atlantic coasts of North America, although those nesting in northern Alaska overwinter in Asia. Many dunlins winter along the Iberian south coast.
The dunlin was formally described by the Swedish naturalist Carl Linnaeus in 1758 in the tenth edition of his Systema Naturae under the binomial name Tringa alpina. Linnaeus specified the location as Lapland.[3] This species was formerly placed in the genus Erolia,[4][5] but is now placed with 23 other sandpipers in the genus Calidris that was introduced in 1804 by the German naturalist Blasius Merrem.[6][7] The genus name is from Ancient Greek kalidris or skalidris, a term used by Aristotle for some grey-coloured waterside birds. The specific alpina is from Latin and means "of high mountains", in this case referring to the Alps.[8]
Ten subspecies are recognised:[7]
Measurements:[9]
An adult dunlin in breeding plumage shows the distinctive black belly which no other similar-sized wader possesses. The winter dunlin is basically grey above and white below. Juveniles are brown above with two whitish "V" shapes on the back. They usually have black marks on the flanks or belly and show a strong white wingbar in flight. The legs and slightly decurved bill are black. There are a number of subspecies differing mainly in the extent of rufous colouration in the breeding plumage and the bill length. Bill length varies between sexes, the females having longer bills than the males. On the tip of the Dunlin's bill is a soft covering that fills with blood and with many nerve endings, forming a sensitive probe that is used to locate invertebrate prey in mud and sand. Although the bill can look sharp-pointed in dead specimens, in life it is blunt.[10]
The call is a typical sandpiper "peep", and the display song a harsh trill.
Dunlin are small migratory waders, however they show strong philopatry with individuals of the Southern Dunlin (Calidris alpina schinzii) in Sweden and Finland returning to, or very close to, their natal patches. Habitat fragmentation has reduced the availability of habitat patches to these birds through reducing patch size and increasing patch isolation. This reduced connectivity between patches has reduced the movements of Dunlin leaving them more susceptible to inbreeding in these locations. Future management for the conservation of Southern Dunlin should include increasing the connectivity between habitat patches.[11]
The dunlin is highly gregarious in winter, sometimes forming large flocks on coastal mudflats or sandy beaches. Large numbers can often be seen swirling in synchronized flight on stop-overs during migration or on their winter habitat.
This bird is one of the most common waders throughout its breeding and wintering ranges, and it is the species with which other waders tend to be compared. At 17–21 cm (6.7–8.3 in) length and with a 32–36 cm (13–14 in) wingspan, it is similar in size to a common starling, but stouter, with a thicker bill.
The dunlin moves along the coastal mudflat beaches it prefers with a characteristic "sewing machine" feeding action, methodically picking small food items. Insects form the main part of the dunlin's diet on the nesting grounds; it eats molluscs, worms and crustaceans in coastal areas.
The nest is a shallow scrape on the ground lined with vegetation, into which typically four eggs are laid and incubated by the male and female parents. Chicks are precocial, however are brooded during early development. They start to fly at approximately three weeks of age. The majority of brood care is provided by the male, as the female deserts the brood and often leaves the breeding area.
Apparent hybrids between this species and the white-rumped sandpiper as well as with the purple sandpiper have been reported from the Atlantic coasts of North America[12][13] and Europe,[14] respectively.
The dunlin has an extremely large range and although the population appears to be decreasing, the population is still very large. The International Union for Conservation of Nature (IUCN) has judged that the threat to the species is of "Least concern".[1] The dunlin is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) applies.[15]
Foraging
Ystad, Sweden
Adult in breeding plumage, Spiekeroog, northern Germany
The dunlin (Calidris alpina) is a small wader, formerly sometimes separated with the other "stints" in the genus Erolia. The English name is a dialect form of "dunling", first recorded in 1531–1532. It derives from dun, "dull brown", with the suffix -ling, meaning a person or thing with the given quality.
It is a circumpolar breeder in Arctic or subarctic regions. Birds that breed in northern Europe and Asia are long-distance migrants, wintering south to Africa, southeast Asia and the Middle East. Birds that breed in Alaska and the Canadian Arctic migrate short distances to the Pacific and Atlantic coasts of North America, although those nesting in northern Alaska overwinter in Asia. Many dunlins winter along the Iberian south coast.