in which Changes of Colour are effected in Moulting. 303 



owls, contrives to get them to live amicably in the same cage 

 with a host of rabbits, guinea-pigs, pigeons, rats, mice, and 

 small birds. A few months ago, I saw in this collection 

 a common kestrel, which had taken to feed a number of im- 

 portunate adult starlings. The man told me that he had had 

 it in his possession about four years ; a circumstance which I 

 was led to doubt, as, from its small size, it was obviously a 

 male bird, and was clad in the livery of the other sex, as all 

 the males are when young. However, on questioning him, he 

 assured me that he had kept it so long ; and incidentally 

 mentioned, as something worthy of remark, that the preceding 

 year it had had what he designated a " pigeon tail ; " clearly 

 alluding to the common adult plumage of the male kestrel, 

 which has the tail grey, with a black bar near its termination : 

 it was therefore more than probable that some injury had 

 deprived it of sexual power, in consequence of which, it had 

 ceased to exhibit the external characteristics of its sex ; nay 

 more, had even acquired the feminine habit of feeding young, 

 as in a capon. 



Now, the above fact, presuming that I do not labour under 

 a misapprehension regarding its verity, would appear to be 

 contrary, rather than analogous, to that of the assumption of 

 the male plumage by female birds that are aged or similarly 

 injured; inasmuch as the same privation would, in the one 

 instance, act as a hinderance, in the other as an immediate 

 cause, of the attainment of the perfect plumage typical of the 

 species. As concerns, however, the fact of female birds oc- 

 casionally obtaining the male livery, I have repeatedly found 

 that this, in particular instances, has no sort of reference to 

 any internal defect. A female scaup pochard, that I lately 

 examined, contained numerous eggs, though in plumage 

 scarcely differing from the male, which I took it to be before 

 dissection ; and I believe the same occasionally happens with 

 the white-eyed pochard. I have seen the hen Lanius rufus vary 

 from considerable dissimilarity to almost exact resemblance of 

 the other sex ; and instances of the same fact, in the allied L. 

 Collurio, have been recorded in former volumes (old series) of 

 this Magazine. The adult male dress is, of course, the typical 

 plumage of a species ; and in every instance, it will be observed, 

 wherein the first or immature garb differs from this, that of 

 the female either entirely resembles the one or the other, or is 

 in various degrees intermediate; in numerous instances, how- 

 ever, manifesting a decided tendency to advance in the scale, 

 in vigorous and healthy individuals. Last winter, I saw a 

 fine bright female of Calamophilus biarmicus, with jetty-black 

 under tail-coverts, as in the male. 



z 4 



