WILD LIFE IN A WEST HIGHLAND DEER FOREST 261 



of the Forest, remain to be mentioned, namely, the House- 

 Martin and the Corncrake. The Martin attempts to rear 

 its young almost annually at the buildings at the railway 

 siding, or at the cottages of the surface-men, but without 

 success, owing to the fact that the nests when completed 

 do not long hold together. This singular circumstance 

 may possibly be due to an insufficiency of clay in the 

 material used in their structure, the only mud available 

 being chiefly of a sandy nature, owing to its being largely 

 composed of disintegrated granite. The Corncrake is repre- 

 sented by a single pair which returns almost annually to 

 a croft of grassland at the foot of Loch Ossian to rear 

 their young. 



III. Valley Zone. This zone lies between the iooo 

 feet contour and Loch Treig (784 feet) on the west, and 

 the slopes above the River Spean (800 feet) on the north. 

 It is a small area outside the stalking ground, but includes 

 the rugged mountain slopes flanking the east side of Loch 

 Treig, a limited portion of the valleys and streams at the 

 head of that fine wild sheet of water, and a belt of rough 

 ground above the Spean. It affords a domicile for the 

 Hedgehog and nesting haunts for a small number of birds 

 not found elsewhere on the Corrour Estate, namely, the 

 Stonechat, Grey Wagtail, Twite, Red-breasted Merganser, 

 and the *Partridge. With the exception of the last-named, 

 these are all summer visitors. Since both of them are more 

 or less subalpine species, one would expect to find the Grey 

 Wagtail and Twite as nesting birds in the middle zone, but 

 as yet they have not come under notice there. The Red- 

 breasted Merganser seems to reach its maximum altitudinal 

 range as a breeding species at Loch Treig, where I have 

 observed it and its brood annually for several years. As a 

 visitor of rare occurrence in the Highlands, the occurrence 

 of a male Lesser Whitethroat among trees at the head of 

 Loch Treig on the 13th of June 191 5 is worthy of mention. 

 The Redshank puts in an occasional appearance during the 

 summer, but its visits are of very short duration. 



Migration. The Subalpine Zone is visited during the 

 spring and autumn by a number of birds which are not 



