- Medium-sized shorebird
- Medium-sized, thin, dark bill with droop at tip
- Black legs
- Black patch on rump extending onto tail
- White wing stripe
- Sexes similar
- White head and breast with faint black streaks and spots
- Black belly
- Rusty mantle with black spots
- White undertail coverts and flanks
- Gray head with pale indistinct supercilium
- Gray breast with indistinct streaking
- Gray upperparts
- White belly and undertail coverts
- Similar to adult basic
- Upperparts rustier than basic adult
- Head and breast with brownish wash
In alternate plumage, the black belly is also found in the Rock Sandpiper.
The Rock Sandpiper has less extensive black on the belly and yellow legs. In
basic and juvenile plumages, the Dunlin is similar to several other species.
It is a darker gray than Western Sandpiper and Sanderling. The Dunlin lacks
the white rump of White-rumped and Curlew Sandpiper. Purple Sandpiper is
darker gray above and has yellow legs. In flight, the Dunlin has a more
substantial wing stripe than peep.