78 ANNALS OF SCOTTISH NATURAL HISTORY 



There are three species of Petrel which visit the island, 

 and they have many things in common. They are all able 

 with outspread wings to run along the surface of the water, 

 patting very quickly with their feet. They are all extremely 

 fat, and have in their stomachs a quantity of pure oil which 

 they can squirt over an assailant. And they all lay but one 

 egg, which is white and very large for the size of the bird. 



The FULMARS [Fulmarus glacialis\ are almost resident, 

 as they only leave about the middle of August and return 

 early in October. They are only away about five or six 

 weeks. They are not, however, every day about the rocks. 

 They only come on shore when the wind is westerly, any 

 point from S.W. to N.W. It weighs about eighteen ounces 

 and is about fifteen inches in length. I have seen a few 

 specimens which were entirely white. The young when 

 about fledged are in general much heavier. I have weighed 

 some which were upwards of two pounds. It begins to lay 

 early in May, and does not select for its nest the more 

 inaccessible rocks, but prefers those places where there are 

 steep grassy slopes with tufts of earth or sorrel. It 

 frequents every slope of this description, numerously in the 

 Island of Soay and St. Kilda, and sparingly in the Boreray 

 group, which are frequented by the Gannet. It lays one egg, 

 which the parents hatch by turns for about six weeks. If 

 the nest is robbed they will not lay a second time. When 

 the chick is hatched both parents take great care of it and 

 feed it most assiduously for six or seven weeks, so that it is 

 generally very fat In a season when the circumstances are 

 favourable a large number of these young birds are killed. 

 On an average twelve thousand will be killed as they are 

 about ready to leave the nest. I estimate that the average 

 number of young Fulmars hatched will be about twenty 

 thousand. These represent forty thousand parents. There 

 are also a large number of birds which either do not find 

 suitable partners or are confirmed celibates, bringing up 

 the total to about fifty thousand. These will take with 

 them about eight thousand young birds when they leave, 

 which seems to be sufficient to keep up their numbers and 

 no more. At times a few old birds are caught by means of 

 the snaring rod, like the Puffin and the Guillemot, but not 



