BISET OR WILD ROCK-PIGEON. 147 



and extensive caves, retiring to their inmost recesses, 

 and generally beyond the situations selected for ni- 

 dification by the auks, gulls, and other aquatic fowl. 

 It is also met with upon the northern and western 

 coasts of Sutherland, the perforated and cavernous 

 rocks which gird the eastern side of Loch Eriboll, 

 and those of the limestone district of Durness, fur- 

 nishing suitable places of retreat, and again upon the 

 eastern coast of Scotland, it is seen about the rocky 

 steeps of the Isle of Bass, and the bold promontory 

 of St Abb's Head. 



The supposition of many of our ornithologists 

 that this and the preceding species were identical, 

 has led to considerable confusion in their writings, 

 and produced a mixed sort of description strictly ap- 

 plicable to neither. The distinctions, however, be- 

 tween the species, even in regard to plumage, are 

 such, that, if attended to, no mistake can well arise, 

 and if accompanied by a corresponding attention to 

 their respective habits, the difference becomes still 

 more apparent and convincing. In one we have a 

 bird the frequenter and inhabitant of the woods, 

 where it roosts, breeds, and perches with security 

 and ease upon the trees, like the ring pigeon and 

 other arboreal species ; in the other, an inhabitant of 

 caves and the holes of rocks, and which is never 

 known, under any circumstance, to affect the forest 

 or perch upon a tree. 



But the rock or wild pigeon is better known to 

 our readers as the inhabitant of the pigeon-house, 



