NOTES ON THE BIRDS OP lONA, 79 



The following notes on the Stormy Petrel and the Red-legged Crow, which 

 I select from his correspondence, will best introduce Mr. Graham to the 

 readers of '^'The Naturalist." — R. G,, Southern^, Oovan, Glasgow^ 



The Storm Petrel, (Thalassidroma pelagica^ 



This interesting and most diminutive member of the great order of Natatores, 

 visits our coasts in considerable numbers during the summer, for the purpose 

 of incubation. On fine calm evenings at this time of the year, after the 

 smooth surface of the deep has put oflF the fiery glow imparted by the setting 

 sun, and begins to assume the dull, leaden tint of night, then the little Petrel 

 may be seen scaring along upon the face of the sea^ now he darts past the 

 fisher's boat as it is rowing along upon its homeward course; is seen for a 

 moment as he flits round the lagging oars, and instantly disappears among 

 the increasing gloom of approaching night. His motions are so rapid, his 

 appearance so sudden, and he looks so extremely diminutive, that it is only 

 a quick eye that will detect his approach at all, and it would be almost 

 impossible for the homewai'd bound sea-fowl shooter to molest him. 



The Petrel breeds upon many of the little wild unfrequented islands which 

 surround lona and StalFa; the latter itself is one station. But upon these islands 

 I have found their nests made in such very dissimilar positions, that it would 

 make one suppose they belonged to distinct species. The first place that I 

 fell in with them was on a little islet about a league south of lona, named 

 Soay. It is high and rocky, with grassy banks on its summit, which feed 

 about a dozen sheep: these banks, which are about eighty feet above the 

 level of the sea, are composed of a soft buttery kind of soil, which cuts, 

 with a spade, like new cheese; and it is in deep burrows formed in this 

 muddy soil that the Petrels make their nest. These banks are perforated by 

 numbers of holes, having the size and appearance of rabbit burrows. If 

 one of these is carefully cut out with a spade, two, or sometimes three, 

 very small apertures, no larger than mouse holes, are discovered opening out 

 of this large entrance, which serves as a lobby to as many distinct Petrel 

 residences. By continuing to dig up the course of these minute galleries, 

 which extend from three to four feet in length, and are at a considerable 

 depth below the surface, we at last come to a small nest composed of a 

 little dried grass, generally of the sea pinJc, loosely laid together, containing 

 a single white egg; the egg is quite warm, and by searching a little further, 

 the bird is sure to be found. It allows itself to be caught and taken up 

 without resistance, only giving a faint squeak, and then ejects about a tea- 

 spoonful of thick yellow oil from -its bill; the quantity and quality of this 

 decreases as the season advances, and latterly ceases altogether: this is 

 probably accounted for by the birds falling off" in condition during the time 

 of sitting. 



The direction of the galleries may be ascertained by thrusting up a ram- 

 rod, for they take frequent and abrupt windings; a large block of the soil 



