VII. 



Iona, 5 th April 1852. 



As to D's remarks about the Petrels' burrows being made by 

 Eabbits, this may be a mere inaccuracy on his part ; or it is very 

 possible that the Petrels take advantage of rabbit holes when 

 they occur upon their breeding stations, as the Puffins and 

 Shieldrakes, I believe, do ; though among our islands these are 

 obliged to make holes for themselves, as there are no Babbits to 

 assist them. The Stormy Petrels' holes at Soay have, exteriorly, 

 very much the appearance of rabbit burrows, but, on excavating, 

 the resemblance ceases ; there would scarcely be room for a 

 Eabbit to conceal his whole body in one. The entrance, though 

 wide, extends but a very slight depth below the surface of the 

 ground ; it immediately contracts into one or two very small 

 passages, only capable of affording ingress to such a diminutive 

 creature as a Mouse or Petrel. These large entrance halls seem 

 to be of great age, overgrown with moss, and the small galleries 

 seem more recently made, or at least re-bored} 



Last year I found a Wheatear's nest formed in the entrance, 

 while the back premises were tenanted by two pairs of Petrels, 

 who must have been forced to walk over the Wheatear's back 

 whenever they came out. None of our small islands contain 

 Eabbits, but if they were once introduced they would thrive and 

 multiply wonderfully. A small rocky islet off the town of 

 1 See remarks in footnote at p. 47, antea. — Ed. 



