Size: L: 35 cm Wt: 250-300 g. Males and females are similar. Seasonally dimorphic. This species requires two years to reach full adult plumage.

Adult winter: mantle grey, with grey on coverts of inner wing, and obvious white division between grey primary bases and black wing-tips; large white tips on all primaries; head with partial hood, dusky to blackish, and with broken white eye ring; underparts white and tail white; bill and legs dark red

Second winter: very similar to adult, but may have black on outer primaries that extends up the outer web, with little or no white division from gray of primary bases; bill dark, may have reddish tip; legs blackish, or dull red

First winter: mantle grey, with brown on coverts of inner wing, and blackish primaries; head with partial hood, dusky; underparts whitish; tail whitish, with black terminal band; bill as in adult; legs reddish-black