Greenland and Iceland Palcons. 243 



all on the same crags. They are a brood \vith their two pa- 

 rents ; there can be no doubt of this, for he saw the old birds 

 bring food to the young ones, and he afterwards found in the 

 same cliffs, and close to the spot where the birds were killed, 

 an old nest which contained in the bottom of it a rotten egg 

 buried in dung. Four of these birds were shot on the same 

 day, the fifth was killed on the following : it was perched near 

 to the nest. I had no difficulty in separating the old from the 

 young, or of naming the sexes. Mr. Proctor's notes taken ia 

 Iceland afterwards proved that I was correct. The old female 

 agrees exactly with the individual brought by Mr. Geo. C. 

 Atkinson from Iceland. The male is similar to the female, 

 only that he is a little brighter in colour, and like the rest of 

 the falcons, is considerably smaller. The young are of course 

 in the nest plumage (they were shot on the 3rd of August) 

 and agree most accurately with the individual taken in York- 

 shire, except that the plumage of the latter is a little faded on 

 account of its greater age. It had undergone six months or 

 upwards extra bleaching. The fading of the plumage is com- 

 mon to all birds. I possess a young peregrine which was shot 

 previous to its moulting, and it is bleached down from the 

 deep brown of the nest plumage to the colour of brown paper. 

 All the young have the bars of the tail non-continuous, and 

 another immature bird which Mr. Proctor also procured in 

 Iceland has the same character. This peculiarity has like- 

 wise been observed by Benwicke, who says, in describing a 

 young bird from Iceland, that " the bars of the tail are non- 

 continuous." I had now before me male, female, and five 

 young of the Iceland or grey species, and on examining these 

 with the male, female, and young of the white or Greenland 

 species, no doubt could exist, and the conclusion was easily 

 arrived at, that the difference of these two birds is not at least 

 the effect of sex or age, unless we adopt the theory common 

 amongst ornithologists, that these birds go on varying in 

 plumage for a series of years, even after they have attained 

 their nuptial dress. This however I shall aftenvards show is 

 not the case. Faber, who resided some time in Iceland, and 

 who is apparently well acquainted with the species of that 

 island, can find no other way of escaping the necessity of ac- 

 knowledging it to be a species, than by supposing that the 



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