52 PLOVER GROUP 



summer arc replaced by greyish brown in winter ; while in Temminck's 

 stint the chestnut edgings to the feathers of the summer-plumage are 

 lost in the cold season. Similarly, the knot in summer is chestnut 

 both above and below, while it is ashy grey in winter, and much the 

 same is the case with the curlew-sandpiper. As another instance we 

 may take the dunlin, in which the feathers of the upper-parts in 

 summer are black relieved by chestnut margins, these being replaced 

 in winter by ashy brown. The redshank shows similar changes in a 

 less marked degree, the general tone being pale brown in summer, and 

 ashy in winter. 



Why certain wading-birds, such as snipe and woodcock, display no 

 marked seasonal colour-change is a question difficult to answer. It 

 may, however, be noticed that in these birds, as well as in the curlew 

 and whimbrcl, the colouring of the plumage is evidently very specialised 

 for protective purposes. Now, it is noteworthy that representatives of 

 the curlew, snipe, and woodcock breed within the British Islands, so 

 that the change between the summer and winter haunts is comparatively 

 slight or nil. On the other hand, many of the waders with a strongly 

 marked seasonal change of plumage, such as the knot, the sanderling, 

 the turnstone, the curlew-sandpiper, and the bar-tailed godwit, breed 

 in the high north, and wander far south in winter, so that the difference 

 between their winter and summer surroundings is enormous. It is, 

 therefore, at least a plausible supposition that their seasonal colour- 

 changes are connected with their migrations, and that they are, 

 in fact, analogous to the changes of this nature which occur in many 

 mammals of the temperate regions, but are unrepresented among 

 tropical species, whose physical surroundings are more or less similar 

 throughout the year. 



In connection with this subject it may be mentioned that in 

 America certain tanagers and bobolinks, which had been prevented 

 from breeding, were kept during autumn in a darkened chamber with 

 a somewhat increased supply of food. The consequence was that the 

 brilliant breeding-plumage was retained throughout the winter. Early 

 in the following spring the birds were returned to normal conditions, 

 and speedily moulted. The new plumage was, however, the nuptial 

 dress, and not the dull winter liver}', which was skipped. The sequence 

 of plumage-change is not, therefore, invariable, but evidently in some 

 degree dependent on external factors in the environment. 



The stone-curlew, or Norfolk jjlover, as it is commonly called, is 

 the typical representative of the famil)' QidicncmidjTj, all the members 

 of which have a strong superficial likeness to bustards, with which they 



