ON SOME SPECIES OF tUt 



No European ornithologist has any doubt of 

 the Hen Harrier and Ring-tail (F, cyanem and 

 -F. 'pygargus) having been properly identified as 

 male and female. Yet supposing the objection 

 urged above to be valid, a North American natu- 

 ralist might with equal justice deny that the dif- 

 ference between the two last- mentioned birds is 

 merely sexual, from the circumstance, as singular 

 and little accounted for, that no bird in the plu- 

 mage of the Hen Harrier has been observed in 

 America, though the Ring-tail is well known 

 there. It thus appears, that, under certain mo- 

 difications of climate, the change in the plumage 

 of the male does not take place, but that of the 

 female is retained ; and this opinion I find con- 

 firmed by a remark of Dr Pallas. " The Ring- 

 tail (he says) is extremely common in Russia as 

 well as in Siberia. In more temperate, and open 

 countries, '^it is certainly not to be distinguished 

 from the Hen Harrier." — Latham's- first Supple^ 

 ment, p. 24. 



What the Falco cyaneiis is in America the Falco 

 alhidus is in Britain, and the history of the changes 

 in the plumage of one species being well known, 

 leaves us in little doubt as to those of the other. 



It still, however, remains a problem difficult of 

 solution, that in one species, a change which we 

 usually consider as allied to those frequently ob- 

 servable in cold climates, should be effected in 

 Trance and Switzerland, and resisted in Britain; 



