420 THE GREBES 



One peculiarity the great crested-grebe shares with its con- 

 geners, and this is the use of feathers instead of grit or stones for 

 digestive purposes that is to say, in the comminution of its food. I 

 have never dissected a grebe whose stomach did not contain feathers, 

 always those of the breast. Why they should display this singular 

 habit is beyond hope of discovery, and it is not the less puzzling 

 because no birds, other than the Grebe tribe, are known to adopt this 

 strange habit of feather eating, save in the case of captive birds, 

 wherein it represents a disorganised condition of health, as in the 

 case of parrots, for example. It would seem that the feathers are not 

 disgorged in the shape of pellets, as in the case of owls and hawks, 

 which swallow a certain percentage of the feathers of their victims, 

 but that they are slowly digested. But then the bolus thrown up by 

 the raptorial birds has formed in the crop ; that which is so commonly 

 met with in the Grebes is always found in the stomach, whence rejec- 

 tion is impossible. I have never taken stones or grit from the 

 gizzards of grebes. 



Has the coloration of the great crested-grebe been in any way 

 determined or controlled by its habits ? It is true this question is 

 applicable to all birds, but it is especially apt in the present species, 

 because it is a species which can readily be kept under observation, 

 and several individuals can be studied and compared at the same time ; 

 and it also presents two distinct aspects of coloration the one, 

 which may be called its environmental coloration, which embraces the 

 whole aspect of the bird at all times of the year, the other its nuptial 

 coloration. This last, while emphatically ornamental, is yet not so 

 vivid in its hues as to be conspicuous save at short range. It may 

 therefore be ignored when considering the character of the plumage as 

 a whole. 



I paid particular attention to this subject some two years ago, when 

 I enjoyed exceptional opportunities for studying these birds on one of 

 the Norfolk Broads. This was during the month of August, when 

 adults and half-grown young could be watched side by side. I had these 



