HYBRIDS BETWEEN RED GROUSE AND PTARMIGAN. 



49 



Capercaillie and Blackcock have mated with the common hen 

 under semi-domestication. None of these hybrids are known to 

 be fertile inter se, and it is very doubtful if any of them are fertile 

 with the parent species. 



But if species belonging to different genera, such as Black- 

 cock (Tetrao) and Willow Grouse or Red Grouse (Lagopus) will 

 cross, it may certainly be anticipated that the more nearly related 

 members of the same genus, such as Red Grouse and Ptarmigan, 

 will under suitable external conditions also produce hybrids. 



All the members of the Grouse family are intimately related ; 

 so much so that a very competent ornithologist (Macgillivray, 

 vol. i. p. 137), speaking of the British representatives of this 

 group, says, " I have hesitated much to admit them as distinct 

 genera"; that is, for example, he has hesitated to recognise a 

 generic distinction between the Blackcock and Red Grouse or 

 Ptarmigan. But if the differences between Tetrao and Lagopus 

 (except as regards feathering and size) be small, the differences 

 between the various species of Lagopus are still less. It has long 

 been a matter of argument amongst ornithologists whether the 

 Red Grouse should not rather be classed as an insular variety of 

 the continental Willow Grouse (L. albus) under the name of 

 L. albus var. scoticus, than as a distinct species ; and after handling 

 many skins of both forms and studying fully the arguments, 

 I certainly hold that our Grouse is not entitled to specific rank. 

 But the connection between the white Ptarmigan, L. mutus, and 

 the Red Grouse is very nearly as close, and their common 

 ancestors cannot be far to seek in time ; the difference of food and 

 surroundings amply accounts for the varying difference in size 

 and colours of the two species : and I can scarcely doubt, after 

 noting the numerous recorded facts showing the close correlation 

 which exists between the size and colour in either species, and 

 the ground which it inhabits, that if some Ptarmigan could be 

 gradually introduced to lower ground, it would not be very many 

 years before their progeny would become assimilated to the Red 

 Grouse both in size and colour. 



Taking, then, the known fact that other and less closely 

 related species of Grouse do cross in nature, and remembering 

 that the ranges of the Red Grouse and Ptarmigan overlap in 

 many parts of Scotland, and that it is not unreasonable to suppose 

 that, once in a way, a solitary cock of the one species may find 



