The Four Keys to ID
- Size & Shape
A very plump, short-necked shorebird with a long, slightly curving bill, and short legs.
Relative Size
Larger than a Sanderling, smaller than a Red Knot.
robin-sizedMeasurements
- Both Sexes
- Length: 7.1-9.4 in (18-24 cm)
- Weight: 2.0-4.6 oz (57-130 g)
© Brian Sullivan / Macaulay Library
- Color Pattern
- Behavior
- Habitat
Regional Differences
Ornithologists currently recognize at least four subspecies of Rock Sandpiper. The largest, ptilocnemis, nests on the Bering Sea islands and winters in Alaska, mostly at Cook Inlet and on the Alaska Peninsula. In breeding plumage, it has a wider white wingstripe, paler underparts, and much paler back than all other subspecies, and its nonbreeding plumage is also noticeably paler. The smallest subspecies, quarta, nests and winters on Russia’s Commander Islands. It has a uniformly colored back. Intermediate in size are the similar tschuktschorum, of mainland Alaska and easternmost Russia, and couesi of the Aleutian Islands. Their breeding ranges meet around Bristol Bay. Both of these darker subspecies show strongly patterned backs in breeding plumage. Most tschuktschorum winter from southern Alaska to northern California, whereas couesi winter near their nesting areas.
