The Storm Petrels arrive at their breeding-grounds towards the middle 

 of June, and eggs are seldom laid before the ist of July. They are very 

 silent birds, and their notes are only heard at their breeding-grounds. Among 

 the heaps of stones on the shore above tide-mark may be heard their faint 

 notes, a plaintive 'tveeet, weeet,' often preceded and followed by a curious 

 guttural rattle. Sometimes the notes are like the distant cooing of a dove, 

 and may be represented by the syllables ' rrrrrrr-coooo-rrrr! In some places the 

 Storm Petrels nest among the ddbris and broken stones at the foot of the 

 cliffs, in others among the stone walls built to protect the sheep, while in 

 many places they nest in the deserted rabbit-burrows or excavate little tunnels 

 for themselves, as on Soa, off lona. In Shetland I found them nesting in 

 the cairns of stone on the summit of Saxaford, some nine hundred feet above 

 the sea. During the day at this locality the birds were quite silent, but as 

 evening came on their plaintive notes could be heard issuing from every 

 little cairn of stones. 



Most of the eggs are laid during the first ten days of July, but I have 

 taken eggs nearly fresh in the beginning of September : probably the first egg 

 had been destroyed. The nest, if such it may be called, seldom consists of 

 more than a dozen pieces of dead grass or straw. The situation chosen 

 is usually beneath some flat stone in a heap of loose rocks, and great care 

 must be exercised in removing the stones, as the tiniest pebble falling on 

 the egg will break the fragile shell. 



Only one egg is laid, rough in texture, with no gloss and an excessively 

 thin and fragile shell. When first laid the egg is pure white, and the yolk 

 inside imparts a pinkish tinge owing to the transparency of the shell ; but 

 after being incubated for a little while it acquires a creamy tint, from continual 

 contact with the oily feathers of the bird. The nest and egg have a strong 

 musky odour, and on Soa, off the south end of lona, it was quite easy to 

 tell the inhabited holes by simply stooping down close to the mouth. The 

 eggs are nearly always thinly sprinkled with tiny reddish brown specks, 

 generally forming an obscure zone round the larger end of the egg. They 

 are usually the same shape at either end, and vary in length from r2O to 

 ro inch, and in breadth from '87 to '80 inch. 



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