INTRODUCTION 21 



male cannot be told from the two- or three-year-old bird. The eclipse is acquired by 

 a nearly complete body and tail moult, usually followed at varying intervals by the 

 single annual moult of the primaries (flight-feathers), the outer secondaries, and 

 some or all of the wing-coverts. The male is then flightless for a time. In certain 

 species the pre-eclipse moult is not nearly so complete as this, and may not involve 

 the back, rump, abdomen, or tail. Sometimes the central tail-feathers are shed 

 before the outer ones, as in the Mallard. 



Usually there is no period of actual stasis in the moulting process throughout the 

 entire summer, for the pre- and post-eclipse moults merge into one another. In some 

 species, however (Ruddy Duck, Blue-winged Teal), eclipse plumage is retained for 

 several months. With the assumption of the new flight-feathers the eclipse may be 

 said to be perfect, although it is often practically so before these flight-feathers are 

 shed. 



The adult male winter plumage is assumed during the second autumn by another 

 (post-eclipse) moult which affects the body -feathers, tail and innermost secondaries, 

 and is often completed by November or December. After this there are two annual 

 moults one of which includes the flight-feathers. 



To return now to the female. Her down plumage is the exact counterpart of that 

 of the males and her first or juvenile plumage is assumed in the same manner. Usu- 

 ally a sexual difference appears in the first plumage which may be appreciated by 

 any one who has handled many specimens, but in some species no differences be- 

 tween male and female can be detected at this time. During the first autumn and 

 winter the young female goes through a moult of the body -feathers, and sooner or 

 later of the tail-feathers, becoming by spring (sometimes by early winter) difficult 

 to tell from a fully adult female, although the juvenile wing is still present. Now 

 comes the difference in the moulting periods of the sexes. The female prepares her- 

 self for the breeding season by a nearly complete body moult, which may take place 

 at any time between autumn and late spring, but occurs typically from February to 

 May. This is a rather slow and easily overlooked moult, which affects most body- 

 feathers, the down, some or all of the tail-feathers, the inner secondaries, perhaps 

 some wing-coverts, but never the primaries or outer secondaries. This moult leads 

 to what may be termed the breeding or summer plumage of the female, a plumage 

 slightly, sometimes strikingly different from the autumn-winter (eclipse of Annie 

 Jackson) plumage. As we shall see, this breeding plumage is retained, although 

 often in a very ragged and faded condition, until the maternal duties are accom- 

 plished, when it is followed by a complete moult in late summer or early autumn 

 affecting the whole body and the wings. Apparently the female does not always 

 become flightless, as does the male, but on this point more information is needed. 

 The typical cycle for the female is now completed, and we see that the two moults in 

 this sex, although they are chronologically delayed in comparison with those of the 



