Size: L: 40cm. Wt: Males: 680 g. Females: 540 g. Sexually dimorphic in size and colour. This species is not seasonally dimorphic.
Male: head dark grey, with white crescent in front of eye, small white head patches, some chestnut on crown; bill stubby, pale grey; white ring around neck, bordered with black; breast and back dark grey, with white and black markings; flanks chestnut.
Female: head brown, with indistinct white facial markings similar to male; body dark, paler on breast.
1st Winter: males similar to adult males, but white markings less clearly defined; females similar to adult females