CYR FALCON— "SPECKLED PARTRIDGE HAWK." 13 



dark \-ariet)-, or stage of plumage of this bird to which I also 

 refer that on the succeeding plate. Coues, in his " Catalogue of 

 the Birds of North America contained in the Museum of the 

 Essex Institute," says, " The Gyr-Falcon which visits New Eng- 

 land is variously given as ' Islandicus,' or ' canciicans.' I do not 

 know which is really the proper name, nor whether more than one 

 species be found. I believe it is still an open question among 

 ornithologists whether these two names do not refer to the same 

 species ; or, in other words, whether there is really more than a 

 single species of G}r-Falcon. Mr. John Cassin in his reply to. 

 some enquiries of mine upon this subject kindly furnishes me with 

 the following: 'I regard the speeies of Hierofalco of North 

 America as the F. candicans of authors {e.g., Bon. Consp. A v. etc.) 

 F. cincereus, Gmelin ; F. Groenlandicus, Daudin ; F. Labradora, 

 Aud. (name on plate) ; F. Sacer, Forster ; whicji last is the name 

 which has priority. 



Mr. Anderson, of Le\-is, Quebec, writes to me under date of 

 15th March,, 1876, as follows: "Taking Prof. Newton's plan, I 

 feel satisfied, at least if the Prof is correct, that my bird is the 

 Falco candicans. I suspected this before, but lacked sufficient 

 data to work upon." This plan of Newton's here I'eferred to is 

 contained in a letter addressed to E. Coues, Esq., M.D., by Alfred 

 Newton, Prof, of Geology in the University of Cambridge, Eng.,'"' 

 in which, after stating that Cassin's notice of the Gyr-Falcon in 

 his " Birds of North America" is all wrong, he writes as follows : 



" The first thing to be fully impressed with is that these large Falcons have 

 exactly the same changes of plumage as Falco Peregrinus or F. A natum (supposing 

 they are distinct), i.c , the young in their first plumage are marked longitudinally, 

 and this plumage they keep until their second oMlnmn, when the fully adult plumage 

 is assumed. In saying this I do not mean to declare that the moult is a matter of 

 a very short time ; on the contrary, I have reason to believe that in most examples 

 it lasts for some months ; but by the end of their second autumn they are in full 

 adult plumage. All that has been said about these birds growing whiter and whiter 

 as they grow older is founded on mere speculation and fancy. The main differences 

 between immature'and adult plumage are that the browns become grays and the 

 longitudinal markings transverse. None of the European dealers understand this : 



* Published in rroc. A. N. S., Phila., 1S71. Part II., p. 94. 



