Calidris alpina
The commonest small wader on UK shores, seen in huge, swirling winter flocks.
Size: 16-20 cm | Habitat: Sea, Marsh, Estuary & Shoreline Birds | Season: All year
A small, active wading bird, the dunlin is the wader most likely to be seen in large numbers on UK mudflats, often gathering in vast, swirling flocks that twist and turn together in flight. In breeding plumage it shows a distinctive black belly patch.
Small size · slightly downcurved bill · black belly patch (breeding plumage only) · streaky grey-brown winter plumage · often seen in large, tightly packed flocks
Dunlins feed by rapidly probing soft mud for small invertebrates, and form some of the UK's most spectacular wader flocks in winter, wheeling and turning together in perfect unison to avoid predators.
Wintering dunlin flocks can number in the tens of thousands on major estuaries, and their synchronised, shape-shifting flight is thought to help confuse hunting peregrines.
The Dunlin (Calidris alpina) is the commonest small wader on UK shores, a slightly downcurved-billed bird that shows a distinctive black belly patch in breeding plumage, best known for forming some of Britain's largest and most spectacular wader flocks.
Dunlins feed by rapidly probing soft mud for small invertebrates, and gather in winter flocks that can number in the tens of thousands on major estuaries, wheeling and turning together in perfect, shape-shifting unison — a behaviour thought to help confuse hunting peregrines.
Despite still being the UK's most numerous small wader, dunlin wintering populations have massively decreased in recent years, moving the species onto the Red list in 2021 — a sign that even Britain's most abundant shorebird is not immune to serious decline.
🔴 Conservation status: Red (UK Birds of Conservation Concern 5)
Red-listed under BoCC5 since 2021, reflecting a massive decrease in UK wintering populations and a moderate decline in breeding range, likely linked to habitat quality changes.