Black-necked Grebe

The Black-necked Grebe is a small grebe, about the same size as the Slavonian Grebe with which it can be confused in winter plumage.
The breeding adult is easily identifiable by its plumage. The head, neck, chest and upper parts are black while the flanks are a bright chestnut brown (the Slavonian breeding adult has chestnut brown neck as well as flanks). The head is remarkable with the black crown plumes and especially the elongated blonde plumes behind the bright red eye. The black beak has a straight culmen and a convex gonys, giving it an upturned look, accentuated if necessary by the mobility of the ramphotheques (see photos).
In the winter, the adult loses its beautiful colours. It is grey, black and white. It is the head that must be looked at closely. The black of the crown, curved in the middle, descends under the red eye and there is a slight grey gradient with the throat, lower cheeks and neck white. The beak is identical. In the winter, the Slavonian has no curved crown and the black/white line under the eye is distinct. But above all the beak is different. The culmen and gonys are convex and give a straight beak and the tip of the beak is white.
In the juvenile, the black upper parts are marked with brown and the lower parts are whitish with the front of the neck greyish. There is no clear boundary on the sides of the head. The eye is brownish reddish. The beak is yellowish and somewhat upturned. The first winter bird has the eye still dull reddish, the front of the neck less dark and the upper parts less obviously black than the adult. The Slavonian in the same conditions is more contrasted, more black and white, but it is the beak that makes the diagnosis. This means that the birds must not be too far apart.