ST. KILDA AND ITS BIRDS. 37l 



single colony of very large dimensions, many of them are 

 nevertheless of considerable size, and in the aggregate 

 their numbers must be very considerable. They are fond 

 of portions of cliff from which large masses of rock have 

 become detached, leaving irregularities of surface which 

 serve as supports for their nests. This bird is not resident, 

 but leaves the rocks in the winter. 



Alca tor da (Razor-bill). 



Very numerous, although much less so than the Guille- 

 mot. The largest colony on the main island is amongst 

 the broken rock masses on a little promontory in the 

 neighbourhood of Miana Stack. It breeds plentifully on 

 Soay, and more particularly so on Dun, especially towards 

 the point, where the huge chaos of rocks and boulders 

 afford it a safe and congenial retreat. The largest colony 

 of all, however, is on Stack an Armin, which I was pre- 

 vented landing on by contrary winds. Like the Guille- 

 mot, if the first egg is taken, they will lay a second and 

 even a third time. They come to the rocks rather later 

 than the Guillemots, but they begin to lay about the same 

 time, and the young are hatched, and leave about the 

 same time as those of the Guillemot. They are never seen 

 about in the winter. 



JJria troile (Common Guillemot and Ringed Guillemot). 



As might be supposed, these birds are exceedingl}' 

 abundant, breeding all round the coasts of all the islands, 

 and on every stack, wherever suitable ledges exist for the 

 deposit of their eggs. Vast numbers of eggs are taken 

 every year for food and for sale to tourists and dealers, 

 and owing to the development of the latter traffic many 

 more eggs are taken now than formerly. It was calculated 

 that last season about 300 eg'gs were obtained for each of 

 the sixteen houses, giving a total of 4,800 ; but last season, 



