Size: L: 30 cm. Wt: 100-120 g. Males and females are similar, with females only slightly larger. This species is seasonally dimorphic. Three subspecies exist, L. g. caurinus, L. g. hendersoni, and L. g. griseus. Only two of these, hendersoni and griseus may be seen on the Great Lakes; these two subspecies differ in breeding plumage, but not in winter plumage.
Breeding Adult, L. g. hendersoni: upperparts dark brown, with dark buff feather-tips, giving scalloped appearance; primaries black; head buffy, with dark crown and eyeline, and dark streaking on neck and cheeks; breast, flanks and belly light reddish, with black speckling; tail buffy to whitish, with obvious horizontal, blackish barring; bill long, straight, black; legs dark olive
Breeding Adult, L. g. griseus: upperparts similar to hendersoni, but darker; primaries black; head buffy, with crown, nape, eyeline, and streaking darker than in hendersoni; breast light reddish, with blackish speckling; belly and flanks light buff to whitish, with black streaking and spotting; tail as in hendersoni, but paler; bill and legs as in hendersoni
Winter Adult, both subspecies: upperparts grey-brown, with faint scalloping; primaries blackish; head, nape, and breast grey-brown, with white eyeline, and faint, dark speckling on breast; flanks white, with blackish barring; belly white; tail as in griseus breeding adult; bill and legs as in all breeding adults
Juvenile, both subspecies: upperparts brown, with light, buffy feather-tips, giving scalloped appearance; primaries blackish; head and nape dark buff; face whitish, with dark buff streaking; breast with buff wash, and dark buff streaking; belly whitish; tail pale buff, with black, somewhat indistinct, horizontal barring; bill and legs as in adults