The comfort movements of Anatidae

Abstract

The comfort movements of Anatidae are described in detail on the basis of observations on 114 species including representatives of all tribes except the Torrent Ducks (Merganetta). A fundamental distinction is made between the occurrence of comfort movements in (1) basic situations (where they are apparently serving their original functions, mostly in caring for the body surface) and (2) secondary situations (where the movements appear irrelevant and unlikely to be serving their original functions). Under ''basic situations'', the form of each movement in the Mallard is described, and attention is drawn to variations occurring in other species. Note is made of the situations in which the comfort movement is performed, and its probable function is discussed. Under ''secondary situations'', an attempt is made to distinguish between instances in which the movement is serving as a social signal and those in which it is not. Comfort movements are classified into seven broad categories : shaking movements, stretching movements, cleaning movements, oiling preening, nibbling preening, washing, and bathing. Most of the nine shaking movements probably function to remove water or foreign material from various parts of the body. The frequency of wing-flapping in White-fronted Geese increases in response to rain and dense fog. Vigorous wing-shaking occurs during oiling and it may have a special function in relation to this activity. Wing-shuffling and tail-fanning are performed after bath…