THE TUFTED-DUCK IN THE NESTING SEASON 267 



feature of incessant occurrence is the pursuit of the females by males 

 of other pairs. The intruding drake, on such occasions, displays his 

 hostility by a characteristic pose, the head being laid back on the 

 shoulders and the tip of the bill slightly raised — an expressive 

 gesture at once recognised by the female, which immediately moves 

 aside. The aggressor then splashes over the surface in pursuit, and 

 the female may seek escape by means of diving, or it may rise on 

 the wing, when the two birds circle rapidly over the water for some 

 short distance before the drake desists from the chase. The mate 

 of the attacked bird makes usually only a half-hearted effort to assist 

 his partner, merely following closely in the rear of the others. The 

 pursuit is seldom continued on the wing to any great distance, and 

 thus is not so obvious a feature as in the case of the Mallard, with 

 which such affairs, originating under similar conditions, may be very 

 prolonged, the birds (most frequently in trios) careering high in air 

 for long distances together. The significance of the trait is not clear, 

 since the drakes of neither species appear to treat their own mates in 

 like manner. 



Like other duck, Tufted-duck pass much of their leisure time in 

 preening the plumage, but there is an aspect of the habit during the 

 few weeks previous to nesting which suggests some particular 

 meaning of its own ; and this is especially the case in the female. 

 When preening in the water under ordinary circumstances, the bird 

 gives a large proportion of attention to the wing-feathers, some of 

 which are passed through the bill, and the bases nibbled and other- 

 wise manipulated. The rump and breast are also attended to, and 

 while working at the latter, the bird tips itself over on its side, and, 

 splashing in the water with one foot, rotates itself with a slow and 

 irregular motion. At intervals the body is raised in the water, and 

 the wings are vigorously flapped, lashing the water into spray. This 

 last action frequently leads on to that form of play most characteristic 

 of the species. The bird shows unusual animation, swimming to and 

 fro in erratic fashion with nodding head, and finally diving 

 excitedly and rapidly, the wings held half-open at the moment of 

 submergence. Such play, which is readily to be distinguished from 

 the more deliberate and systematic diving for food, is thus very 

 similar to the diving of the Mallard in like conditions, but is perhaps 

 less common of occurrence and performed with less abandon than 

 in the latter species. The features of preening which seem to be 

 more typical of the nesting season, are best seen in a duck ashore, 

 as is so often the case at that time of year. Standing in a semi-erect 

 attitude, the bird confines its attention largely to the upper part of 

 the breast, nibbling and pulling at the bases of the feathers, and 



