LETTERS OF AN ORNITHOLOGIST. 



(Continued from Vol. II, page 164.^ 



Letter III. 



lona^ April 5th.^ 1852. 



As to D's remarks about the Petrel's burrows being made by [Rabbits, 

 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 Rabbits 

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

 much the appearance of Rabbit-burrows, but, ou excavating, the resemblance 

 ceases: there would scarcely be room for a Rabbit 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 ov tivo very small 

 passages, only capable of aiFording ingress to such a diminutive creature as a 

 Mouse or Petrel. These large entrance halls seem to be of great age, over- 

 grown 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 Rabbits, but if they were once introduced they 

 would thrive and multiply wonderfully. A small rocky islet off the town of 

 Tobermory, called Calve Island, was thought to be turned to some account 

 by a former proprietor, who stocked it with Rabbits of a superior breed. In 

 the course of time these so destroyed the pasture that a later proprietor 

 wished to get rid of them; but they utterly defied all his efforts to extirpate 

 them. Rabbits are abundant in lona now, yet the man is still alive who 

 introduced the first pair into the island. Hares were also very recently 

 introduced into Tiree island. I have frequently met with Hares upon little 

 islets a quarter of a mile from the mainland, which they must of course have 

 reached by swimming; but Rabbits I think never take the water, even for the 

 shortest distance, though they frequent the sea-shore for the sake of sea-weed. 

 There are some tempting islands hardly a gunshot from the mainland of lona, 

 which arc never visited by Rabbits. 



Most of the small islets and rocks within a moderate distance of the coast 

 are infested by Rats, which subsist upon the shell-fish, crabs, birds' eggs, 

 etc. Fortunately these rascals have not reached Soay; it is too far out for 

 them, clever swimmers as they are. If they once get a footing there, they 

 will quickly banish Petrels, and every other bird from nestling there more. 

 I was often disappointed during the egg season, when searching for sea-fowls' 

 eggs, to find many promising- looking rocks untenanted; but I soon discovered 

 that the cause of it was the Rats had penetrated to them, and the birds 



VOL. III. E 



