S02 Reconciliation of apparent Discrepancies in the Mode 



when young, retains its broken quill-feathers till the second 

 autumn : indeed, it is furthermore observable, in the latter 

 instance, that, while a young cock blackbird becomes otherwise 

 wholly black at the first moult, its brown nestling quills pre- 

 sent an obvious contrast till the next general change of feather ; 

 and this while it is equally perceptible that the brown nestling 

 primaries of a starling of the same age had been changed, 

 from the absence of corresponding diversity. A recourse to 

 the measure will generally determine which species moult in 

 either way ; for, in those which shed their nestling quills the 

 first season, these, with few exceptions, will be found much 

 shorter than the feathers by which they are succeeded : the 

 same applies equally to the tail; besides which, in most in- 

 stances where, the latter deviates from an even form, the 

 approach to this is greater in the young. It would be need- 

 less, however, to enter into long details of exemplification, my 

 object being rather to show that attention to these and many 

 similar minutiae is oftentimes of the greatest assistance in 

 enabling us to trace out correctly the affinities of groups: for 

 instance, the tits (Parus), of which the general characters are 

 intermediate between those of the warbler and corvine genera, 

 invariably retain the wing primaries, like the former, and 

 moult their tail-feathers, as in the latter, at the first autumnal 

 change of plumage. 



There are many other birds, however, as the Falconidae 

 and true gulls, which undergo no change of feather till the 

 second autumn, though some of these exhibit a manifest change 

 of colour before the moulting time. I have particularly noticed 

 this in the male Circus cineraceus, and the Lurus argentatus, 

 both of which I have known to become almost wholly grey 

 previous to the casting of their first plumage. The common 

 kestrel may be sometimes observed to throw out a few adult 

 feathers during the first autumn ; but, out of many dozens of 

 them that I have examined in the winter months, 1 have 

 never yet seen one that had renewed more than a very few of 

 its feathers : indeed, the disposition to change them ceases, as 

 has been already noticed, in the course of a few weeks ; and 

 the dissimilar old and new feathers are retained together till 

 the second autumn ; there being, in this instance, no ten- 

 dency to a change of colour in the existing plumage. 



Having mentioned the kestrel, I cannot do better than 

 introduce here a notice of a most interesting fact, which I have 

 learned respecting the plumage of a bird of this species. Few 

 Londoners are unacquainted with an exhibition to be seen 

 constantly, in fine weather, upon Southwark Bridge, where a 

 man, by everlastingly gorging a number of cats, hawks, and 



