Dunlin (Calidris alpina)
Dunlin (Calidris alpina)
Dunlin (Calidris alpina) – Master of Migration
Few shorebirds are as commonly seen during migration as the Dunlin. Its spectacular flocks fly in perfect synchrony, rapidly changing direction in a mesmerizing display—reminiscent of swirling cloud formations.
With its slightly curved bill, the Dunlin is an expert forager, and its distinctive black belly patch in breeding plumage makes it unmistakable. In summer, it breeds in the Arctic tundra, but in winter, it moves to the coastal regions of Europe and Africa, searching for food in tidal mudflats.
Whether in the Arctic or along European coasts, the Dunlin is a true symbol of bird migration and a remarkable survivor of nature’s challenges.
Table of Contents
- Key Facts
- Appearance & Features
- Habitat & Distribution
- Breeding & Nesting
- Calls & Behavior
- Diet & Foraging
- Shortlist – All Key Facts at a Glance
- FAQ – Frequently Asked Questions
- Conclusion
1. Key Facts
- Size: 17–21 cm
- Wingspan: 32–36 cm
- Features: Variable, slightly curved bill, dark belly patch in breeding plumage
- Range: Breeds in the tundra, winters in Western & Southern Europe and Africa
- Breeding: Ground nest, well camouflaged in dense vegetation
- Diet: Insect larvae, worms, small crustaceans
2. Appearance & Features
The Dunlin is a medium-sized, compact shorebird with a streamlined body, perfectly adapted for life between coastal mudflats and tundra wetlands.
Distinctive Features
- Breeding Plumage:
- Dark gray upperparts with rusty flecks
- Distinct black belly patch
- Bill is moderately long and slightly down-curved
- Non-Breeding Plumage (Autumn & Winter):
- White underparts, grayish upperparts
- Less contrast than in breeding plumage
- Juvenile Plumage:
- White “V” pattern on shoulders and back
3. Habitat & Distribution
Breeding Grounds
- Arctic tundra, subalpine wetlands, mountain moors
- Prefers coastal grasslands and salt marshes
Wintering Areas
- Tidal mudflats, coastal estuaries, inland wetlands
- Found from Western & Southern Europe to Africa
During migration, Dunlins often form large synchronized flocks, moving in unison with sudden directional shifts—a breathtaking spectacle of nature.
4. Breeding & Nesting
- Nests are well hidden in vegetation to avoid predators.
- Clutch consists of 3–4 eggs, incubated by both parents.
- After 19–21 days, the chicks hatch and are cared for by both parents.
- Dunlin chicks are precocial, leaving the nest just hours after hatching to forage independently.
5. Calls & Behavior
Calls
- Trilling “trrrü” or “kirrp”, often heard in flight
- Males produce rapid buzzing and trilling sequences during breeding displays
Behavior
- Forms large, tightly packed flocks with synchronized flight movements
- Groups execute sudden, precise turns when threatened
- Feeds by alternating between running and abrupt stops, probing for prey
6. Diet & Foraging
Diet in Breeding Areas
- Insect larvae, especially midges and mosquitoes
- Small crustaceans and mollusks
Diet in Wintering Areas
- Marine worms, small mollusks, crustaceans
- Occasionally feeds on tiny snails and shellfish
Foraging Technique
- Probes into mud or sand with its slightly curved bill
- Uses precise bill movements to detect hidden prey
7. Shortlist – All Key Facts at a Glance
- Size: 17–21 cm
- Wingspan: 32–36 cm
- Features: Slightly curved bill, black belly patch in breeding plumage
- Habitat: Tundra, coastal wetlands, salt marshes, mudflats
- Nest: Ground nest, camouflaged in grass
- Call: Trilling “trrrü” or “kirrp”
- Diet: Insect larvae, worms, small crustaceans
8. FAQ – Frequently Asked Questions
How do you recognize a Dunlin in flight?
Dunlins display synchronized flock movements, and in winter, their contrasting wing markings make them easy to identify.
Why does the Dunlin have a black belly in summer?
The black belly patch in breeding plumage likely serves as camouflage against the darker tundra ground, helping it blend in.
What are the biggest threats to the Dunlin?
- Climate change: Alters Arctic breeding habitats
- Habitat loss: Coastal mudflats are being degraded by human activities
- Disturbance by tourists and off-leash dogs in wintering areas
9. Conclusion
The Dunlin is one of the most fascinating shorebirds, known for its synchronized flocking and adaptable feeding behavior. Its black belly patch in summer makes it easy to recognize, while its coordinated flight displays are a spectacle in themselves.
Tip for Birdwatchers: The best time to see Dunlins is during winter along the Wadden Sea or shallow coastal mudflats, where they gather in large numbers to forage.
