ANIMALS INTRODUCED FOR SAKE OF SPORT 271 



breeding grounds. This is exactly what was found to take 

 place. Fortunately the years that intervened between its 

 extinction about 1770 and its introduction in 1837, were 

 years fruitful in planting, and in the interval, woods largely 

 of coniferous trees had sprung up on the hillsides and 

 along the valleys of many of our rivers. Dr Harvie-Brown 

 was of opinion that the Capercaillie viewed prospective sites 

 from its old establishments, and this very probable selection 

 by sight, together with the fact that most of the woodland 

 lay along the water-courses, would determine the Caper- 

 caillie's dispersal along the valleys. Indeed, judging from 

 the dates of the advent or establishment of birds in new 

 areas, the valley systems ranked second only to the presence 

 of- fir-woods in determining the course of the migrating 

 Capercaillies. It is a curious feature of these migrations, 

 that, as a rule, hen birds alone prospect new dwelling-sites, 

 and commonly settle in a new area two, three or four years 

 before any cock bird arrives. During the interval before the 

 coming of their true, even if polygamous, partners, the hens 

 frequently mate with the closely related Blackcock (Tetrao 

 tetrao], and even with the Pheasant, the result being that 

 the extending margin of a Capercaillie country is marked by 

 the presence of hybrid birds. 



The Tay and the Forth valley systems offer highly 

 instructive evidence of the influence of such routes on the 

 dispersal of a species. Follow for a moment, with the aid of 

 the accompanying map(Map I), the Capercaillie's wanderings 

 from the centre at Taymouth Castle, at the east end of Loch 

 Tay, where it was established in 1837. I gi ye as a ru ^ e 

 the earliest recorded appearance at any particular place, but 

 have ignored sporadic occurrences clearly out of touch with 

 the general movement of the birds. From its dispersal- 

 centre the " Caper " followed the valleys radiating east and 

 west from the northern end of Loch Tay. It reached the 

 meeting place of Tummel and Tay in 1844, and passing 

 north and south along the valleys, reached Blair Athole on 

 the Garry in the following year, sending off, by the way, a 

 side branch which followed the Tummel itself to Loch 

 Rannoch. 



The main migration down the Tay was well defined. 

 It reached the junction of the Isla shortly after 1847, and 



