Dunlin

Highly distinctive and medium-sized, this scolopacid wader measures between 17 and 21 cm in total length, features a wingspan of 32 to 36 cm, and exhibits a body mass ranging from 40 to 85 grams. The body profile is compact, supported by medium-short, blackish legs and accentuated by a moderately long, dark bill that displays a characteristic, gentle downward curvature toward the tip. Breeding adults exhibit a rich, variegated mantle of chestnut-red and black, perfectly complemented by a conspicuous, diagnostic black belly patch set against a contrasting white, finely streaked chest. The non-breeding plumage is muted and brownish-gray across the upperparts, accompanied by white underparts with faint, washed-out breast markings. Sexes are largely monochromatic, although females tend to display slightly longer bills and a fractionally greater body mass compared to males.

Geographical distribution: It possesses an extensive circumpolar distribution across the Holarctic, establishing breeding territories throughout the high-latitude zones of the Arctic and subarctic. Key nesting territories span the northern coastal tundras of Alaska, the Canadian Arctic Archipelago, coastal fringes of Greenland, Iceland, northern Fennoscandia, and northern Russia across the Siberian coastline. During the boreal autumn, it carries out extensive migratory movements to temperate, subtropical, and tropical coastal regions, wintering extensively along the Atlantic and Pacific shores of North America, the coastlines of Western Europe, the Mediterranean Sea, maritime regions of North and West Africa, and extending into coastal East Asia, including Japan and southern China.

Habitat: Breeding grounds are fundamentally located in moist, open environments such as wet tussock tundra, polygonal peat bogs, subarctic moss-rich heathlands, and shallow swampy depressions. Along migratory stopovers and throughout the wintering period, it becomes heavily reliant on marine littoral ecosystems, congregating in extensive intertidal mudflats, estuaries, salt marshes, coastal lagoons, and exposed sandy beaches. Although marine coastal environments represent its primary non-breeding niche, smaller aggregations regularly utilize freshwater stopovers, including margins of shallow interior lakes, sewage treatment ponds, flooded agricultural land, and riverine sandbars.

Feeding: Operating as a carnivorous tactile forager, it targets a wide array of benthic invertebrates buried in wet substrates. In estuarine and coastal marine zones, its primary sustenance includes marine polychaetes, minute bivalves, tiny gastropods, and amphipod crustaceans. On northern breeding grounds, dietary preference shifts sharply toward terrestrial and freshwater arthropods, primarily larvae and adults of chironomid midges, crane flies, water beetles, and spiders, occasionally ingested alongside small wetland seeds. Feeding involves a characteristic, energetic "sewing-machine" motion, repeatedly thrusting the bill downward into muddy substrates to detect prey items through specialized tactile receptors clustered at the bill tip.

Behavior: Highly social outside the nesting season, it convenes in vast, densely packed aggregations that frequently perform mesmerizing, highly synchronized aerial evasions to confuse avian raptors like falcons. Daily activity patterns are strictly governed by tidal fluctuations, forcing birds to roost communally on elevated sandspits or salt marshes during high tide and dispersing promptly to forage as the receding waters expose invertebrate-rich mud. In the breeding season, solitary pairs become territorial; males advertise occupancy through musical trilling vocalizations delivered during hovering display flights, which conclude in gentle, butterfly-like glides back to the tundra turf.

Nesting: Nest construction takes place directly on the ground, favoring elevated, drier hummocks, sedge tussocks, or vegetated peat ridges to minimize flood risk. The male scrapes several shallow cavities, from which the female selects one to line meticulously with dwarf willow leaves, dried grasses, and small lichens. The clutch consistently numbers four subelliptical eggs, showing an olive or buff background marked with deep brown or purplish blotches. Both adults undertake incubation duties over a span of 21 to 22 days. The resulting precocial chicks emerge coated in protective, camouflaged down; they vacate the nest cup within hours of hatching, foraging independently while being brooded primarily by the male until attaining flight capability at 19 to 21 days.

Conservation status: The species is currently cataloged as Least Concern (LC) on the IUCN Red List of Threatened Species. Despite its large global census and wide distribution, distinct geographical subspecies and populations—particularly within temperate Europe and portions of East Asia—are undergoing notable local declines. Substantial hazards encompass the loss and reclamation of tidal mudflat habitats, climate-induced shifts in tundra ecosystems, environmental contaminants in estuarine sediments, human recreation disturbances, and sea level rise driven by global climate change.