244 Mr. J. Hancock on the 



white or Greenland bird is " either an Iceland falcon in a very 

 advanced age, or what'' he is " much rather disposed to be- 

 lieve, an albino variety." With regard to the former part of 

 his supposition, there is nothing that I am aware of in the hi- 

 story of the Falconidee to warrant such an assumption. They 

 do not, like most birds, shed the nest plumage in autumn, but 

 retain it until the following spring, when they get the mature 

 dress, and I know of no instance of any subsequent change of 

 importance. This is the case with the peregrine falcon, which 

 is very closely allied to the Iceland species. This fact is well 

 known to falconers, though I believe doubted by many orni- 

 thologists. Capt. Bonham of the 10th Hussars, who has for 

 many years kept a number of peregrines, showed me an indi- 

 vidual which had got its mature plumage, and it was then only 

 a year old. It had retained its nest plumage until the spring, 

 when it moulted and at once assumed the mature dress, and 

 he assured me this was always the case. This also takes place 

 with the kestrel {Falco Tinnunculus, Linn.), and I believe with 

 all the true falcons : occasionally the plumage may afterwards 

 become a little brighter, but never any material change takes 

 place ; the markings retain their characters, and though the 

 i bird may be considered a finer and more distinctly marked 

 ^ T\ individual, yet the plumage is identically the same in all es- 

 sential points. We possess, however, the strongest proof that 

 this is the case with the Iceland species. The Yorkshire spe- 

 cimen, though in the nest plumage, has, as before remarked, 

 got several new feathers which are exactly like those of the 

 adult, breeding individuals from Iceland ; thus we have a proof 

 that this species gets the mature plumage immediately on shed- 

 ding the nest feathers ; and in the two old birds we have evi- 

 dence of the strongest nature that their plumage undergoes no 

 further change, for it fortunately happens that they are also in 

 the process of casting their feathers, and those that are coming 

 are perfectly similar to the feathers of the previous year. No- 

 thing can be more decisive. It needs no comment. The Ice- 

 land species then does not change after it has attained the 

 breeding dress. Faber also remarks, that the Iceland bird is 

 not mature, that is, it does not breed until it has got yellow- 

 legs : this is probably the fact ; then if he be correct in sup- 

 posing that the white or Greenland species is only an Iceland 



