162 



RIVER AND POND DUCKS 



the adult male is in the plumage recognized as that of the Red-legged Black Duck,, 

 but that earlier in the season, in the preliminary stages of the moult, the colours of 

 bill and feet more closely resemble those ascribed to the Common Black Duck.) 



ADULT FEMALE. WINTER PLUMAGE: (Note that this description of the female, 

 particularly in respect to the colour of the bill and feet, conforms to that which is 

 usually ascribed to the Common Black Duck.) Female closely resembles male in 

 winter plumage except (a) feathers of sides of chest 

 have pointed, V-shaped buff markings, which, however, 

 may be lacking in some birds (these marks are rounded 

 or U-shaped in male), (b) bill generally shorter, and 

 greener or more olive yellow than that of male; usually a 

 dusky blotch on ridge and often small black spots on 

 sides of upper mandible (in a very few old females 

 bill may be plain yellow and may lack dusky markings), 

 (c) feet brownish, with usually some orange or salmon 

 colour; some older females have feet as brightly coloured 

 as juvenile male in late autumn; colour of feet shows 

 great variation. 



Feathers from sides of 



chest of adult female 



Black Duck. 



POSTNUPTIAL PLUMAGE: This plumage is acquired by a 



moult which may commence as early as March or April; it resembles the winter 

 plumage except (a) feathers of chest are plain dusky without V-shaped buff markings 

 on centers, (b) feather-edgings tend in general to be narrower. Annual shedding of 

 wing-feathers takes place during this moult. During a second moult from September 

 to October this plumage is replaced by winter plumage, described above. 



JUVENILE. (Note that this plumage, particularly in respect to the colours of the 

 bill and feet, conforms to that usually ascribed to the Common Black Duck.) 



By the beginning of September sexes are much alike and resemble adults 

 except (a) sides of feathers of chest and breast widely margined with buff, but 

 dark center of feathers reaches to tip, giving very streaked ap- 

 pearance to underparts. All body-feathers narrower than in adult, 

 (b) U-shaped or V-shaped markings on feathers of sides of chest, 

 present in adult, are lacking, (c) less contrast between colour of 

 head and neck, and colour of rest of body, (d) tail-feathers nar- 

 rower, with usual blunt structure (fig. 26), (e) bill of young male 

 in early autumn yellowish olive. (Colour change of bill takes place 

 very shortly after death); bill of young female at this time dusky 

 or olive grey, with blackish spots on upper mandible, (f) feet of 

 breast feather y un g male orange brown; feet of young female brownish, some- 



of juvenile. times with olive tin g e - 



From September to November inclusive, juveniles undergo 



a continuous moult of body-feathers, tail and tertials, during 

 which juvenile plumage described above is progressively replaced by first winter 

 plumage, similar to that of adult. The narrow body-feathers, with the broad buffy 

 side-edging, are gradually replaced by wider, completely buffy-edged feathers, and 

 the U-shaped or V-shaped ones of the adult chest-plumage are acquired. Bill of 

 young male gradually changes from yellowish olive to yellowish, approaching orange 

 yellow of adult by January. (Colour change of bill takes place very shortly after 

 death.) Bill of young female changes very gradually from dusky towards the yellowish 



Chest and 



