1886. } MR. R. COLLETT ON HYBRID GROUSE. 233 
again to his gun. The knowledge of its life and habits therefore 
amounts to almost nothing, and no observations have been made in 
Norway which can give any information concerning its origin. 
The existence of this hybrid arises from the fact that both parents 
not unfrequently inhabit the same localities. Thus Tetrao tetrix in 
the southern valleys of the land, where most of these liybrids are met 
with, regularly ascends to the elevated birch-forests on the mountains, 
and establishes itself in the regions where Lagopus albus has its 
proper home. On the other hand, but more rarely, Lagopus albus 
descends and breeds in the upper portions of the conifer-woods, 
where the other species is still to be met with in numbers. 
In the northern portions of the country, however, where both 
species live almost at the same elevation above the sea, and still more 
commonly share the same place of residence, the Tetrao tetrix on the 
whole appears in much lesser numbers than the other species, and 
the hybrids are here apparently more rare. 
It is not easy to understand the true reason for the pairing between 
two species so different in their habits, appearance, and nature. One 
of the specimens obtained in Norway was shot at a place (Saltdalen 
in Nordland) where no want of mates of either species could be 
observed in the neighbourhood. Connections of this kind are _ 
repugnant to nature, and in many cases the only feasible explanation 
is to be found in imagining a violent and irresistible desire to breed 
out of the species. 
Concerning the question of the origin, it is first of all necessary to 
find out whether one or two sorts of such hybrids exist—the one 
bred between the male Lagopus albus and female Vetrao tetriz, the 
other between the male Z'etrao tetriv and female Lagopus albus’. 
But as it is an established fact that all individuals hitherto found 
(with us) of the Rype-Orre, if obtained at the same season of the year, 
are on the whole singularly alike both in size and the colouring of 
their plumage, their origin cannot be ascribed to more than one of 
the two possible connections. 
When Prof. Nilsson in 1817, in his ‘ Ornithologia Suecica,’ treated 
of its descent for the first time, he mentions it (p. 303) as 
“ Hybridus a Tetrice patre et Tetr. subalpino femina”*. This 
assumption that it is the male of Tetrao tetriz which has formed 
an illegitimate connection with the female of Lagopus albus (as 
it is also the Blackcock that with the female of Vetrao wrogallus 
produces the ‘“ Rakkelfugl”), has always been and is still gene- 
rally accepted by most naturalists. Upon this theory it has 
received the names :—Tetrao lagopoides, Nilss. Skand. Fauna, 1st 
ed. (1828), and 7'etrao lagopides, 2nd ed. (1855); Yetrao lagopodite- 
tricides, Sundev. Svenska Fogl. p. 255 (186-2), (being the descendant 
of Tetrao tetriz, mas, it had to bear its generic name) ; and, finally, 
1 A hybrid between Lagopus mutus and Tetrao tetrix is rather improbable, 
on account of the very different haunts of these species. 
2 * Qui vero videt (illas) varietates, non diutius dubitare potest de libidine 
Tetricis ad furtivos amores cum congeneribus instituendos semper paratissima.’’ 
(Nilss. 7. c.) 
Proc. Zoou. Soc.—1886, No. XVI. 16 
