288 SEA-BIRDS 



At last the young bird proceeds to the sea, alone and always at night, 

 when the attacks from the predatory gulls and skuas are least likely. 



In very dry summers, or in those burrows in dry sandy soil, the 

 young puffin may be heavily attacked by red mite. Many may at this 

 stage be so severely sucked by this ground-breeding parasite that they 

 die through loss of blood. On the island of Burhou in the Channel 

 Islands in June 1949, we found several hundreds of fledgeling puffins 

 dying or dead, in or near their burrows, and covered with blood- 

 sucking mites, identified by the British Museum as Dermanyssus gallinae, 

 commonly known as the poultry mite. Ticks [Ixodes uriae) attack adult 

 puffins in late spring and summer; often the white face of a puffin will 

 be quite grey with the bloated bodies of these bloodsuckers, which 

 are picked up in the grass and the burrows, and which drop off after 

 a few days feeding, as soon as they are engorged. 



At dawn on late July mornings the sea surrounding the islands 

 where puffins breed numerously will be dotted with young puffins 

 which have made their way to the water during the night. They have 

 scrambled over the rocks or fluttered down from high cliffs. The 

 strong tides will help to sweep them away to sea. The young bird 

 paddles vigorously (for as yet it cannot fly), showing anxiety to get 

 out into the open ocean. If attacked by a gull, it escapes by diving. 

 The adults take no interest whatsoever in the fledged puffin when they 

 encounter it in the water at this time of the year. Nor does the young 

 bird betray, by calling or other sign, the slightest interest in the adult, 

 except that it will usually swim away from, rather than towards, a 

 raft of adults. It is worth noting that in those species described in 

 this book which make a night passage to the sea at fledging time, 

 there is this complete desertion of the young bird. These two events 

 in the breeding biology of these species seemed to be linked with the 

 factor of rearing in the darkness of a burrow; the adults, except in a 

 few instances where a burrow happens to be short and well-lighted 

 from the entrance, have never properly seen their chick, and are 

 familiar with it only as a voice and a form in the twilight underground. 

 They probably could not recognise it visually at sea in daylight, nor 

 is it necessary for them to do so. 



The young puffin, like so many other migratory birds, has to find 

 its way alone to the wintering ground of its kind, to the gathering 

 place of all juvenile puffins of its own subspecies which have left the 

 islands and cliffs in early autumn. But little is known of this movement, 

 or of how the juveniles meet with the adults, if they do, on the return 



