Mr, J. Hancock on the Greenland and Iceland Falcons. Ill 



the tail is not uncommonly devoid of all markings. Other nest 

 birds are comparatively dark, vriih the spots large and crowded. 

 The former, on maturity, are very little spotted, and have all the 

 under parts, head and tail not unfrequently pure white ; the 

 latter never attain the same degree of whiteness, but change 

 into the dark and richly marked varieties of the adult. 



There is no doubt with regard to the mature and immature 

 state of this species. I possess several specimens with the 

 large oblong markings of the nest plumage, which are moulting, 

 and in evei-y case the new feathers have the cordate spots of 

 maturity ; and to show that no change takes place afterwards, it 

 is only necessary to refer to the beautiful specimen which was 

 kept alive in the Zoological Gardens, Regent^s Park. This indi- 

 vidual was a male ; it had the plumage very light ; and when I first 

 saw it in 1849 it exhibited both mature and immature feathers ; 

 the old and faded ones, on the upper parts, having the oblong 

 spots of the first plumage, the new feathers of the back and 

 scapulars being all marked with cordate spots. I took a drawing 

 of the bird in this state. On completing its moult it was one of 

 the whitest specimens I have ever seen. It lived until May 1852, 

 and must consequently have changed its plumage twice after 

 having assumed its mature dress ; but no further alteration took 

 place in the form of the markings, and the bird was as white on 

 its first moult as it was when it died. Another living specimen, 

 which I had in my possession some years ago, moulted once. 

 This was mature when I received it, and it was as white then as 

 after its moult ; and no change whatever took place in the cha- 

 racter of its plumage. It may also be stated that I have several 

 specimens in the mature plumage which have partially cast their 

 feathers, and those coming are exactly like the old ones — neither 

 darker nor whiter — the feathers of the iipper parts bearing the 

 same characteristic cordate spots. Thus there appears ample 

 proof that the birds with oblong spots on the upper parts change 

 at once into those with cordate spots, and that the latter undergo 

 no subsequent alteration; the one is therefore evidently the 

 young of the other, and is undoubtedly in the first or nest plu- 

 mage, unless this species be an exception to the rule, that all the 

 true falcons get the mature plumage on the first moult : the Ice- 

 land falcon, peregrine, merlin, hobby, red-legged falcon and 

 kestrel all do. 



Falco Grcenlandicus then differs from F. Islandicus in both the 

 mature and immature states, and is characterized by its greater 

 whiteness of plumage. The former, in fact, may be stated to 

 have white feathers with dark markings, the latter dark feathers 

 with white markings ; besides that the mature Iceland falcon is 

 further distinguished by conspicuous transverse bands above and 



