70 EDWARD A. WILSON. 



without exception, it was given with the wing, and the claws were never used in 

 the attack. While her partner was thus doing his best to frighten off the intruder, 

 the sitting bird was loudly and persistently advertising the exact position of the 

 nest, nor would she leave her post till we had come, sometimes, to within a yard 

 or two. 



The bird's cry is much like that of other gulls, a loud and anxious rapidly 

 repeated cry, and very harsh. But the cry of the fledgling is very different. At Cape 

 Adare I thought for some time that there must be a bird of the sandpiper type about, 

 for I constantly heard a liquid, melancholy whistling trill. By degrees, however, 

 it brought me to a fledgling Skua, which was just beginning to use its wings for 

 flight. I saw it whistling with a most musical note, wholly unlike the harsh cry of the 

 adult. 



The bird makes no attempt at concealment, though its colour as well as the colour 

 of its eggs might be considered to be specially adapted to the nature of the ground, 

 but with such habits as the Skua's there is obviously nothing in it. Even when the 

 bird is away from its nest, one has but to climb a little rocky hillock, and somewhere 

 in the hollows under one's eye will be apparent two eggs in a shallow scooped-out nest, 

 easily visible even at a distance of ten or twenty yards. There is never any attempt 

 at nest-making other than the shallow depression in the gravel on which the eggs are 

 laid. Once only I found a little collection of the Adelie penguin's tail feathers laid in the 

 hollow, as one occasionally finds a little twig or a few bents laid in the hollow of a 

 Peewit's nest,* but as a rule in a Skua's nest there is nothing at all. We never found 

 more than two eggs in a nest, and in a certain number of cases in every rookery one 

 egg is considered sufficient for incubation, the other doubtless having been stolen by a 

 marauding neighbour. In many cases there is to be found in company with a normal 

 egg another with a much thinner shell and a pale bluish ground, but with little or no 

 marking. Sometimes a thin-shelled egg may be ringed round the upper third by 

 minute and crowded dots and speckles, but be lacking in the characteristic blotches of 

 the normal egg. These I took to be the results of an effort to replace a stolen egg, the 

 amount of shell and colour that the bird is able to secrete being nearly exhausted in 

 the production of the first two eggs. In one nest I found a normal egg in company 

 with another the size of a Blackbird' s.f All round the colony, in addition to the 

 empty shells of sucked penguins' eggs, are to be found the shells of Skuas' eggs bearing 

 similar evidence of theft and suction. 



A very favourite nesting site in McMurdo Sound was a group of moraine-covered 

 islands on the western side, now known by the name of Dailey Islands. At Dellbridge 

 Islands, also, on the eastern side of McMurdo Sound, we procured large numbers of 

 Skuas' eggs, but neither here nor at the Dailey Islands did the rule hold that Skuas 

 always breed near penguins, for in each case they were quite alone. 



* Peewit = Vanellus vulgaris. 

 t Blackbird = Turdus mertila. 



