THE COMMON SKUA. 375 



nests are sometimes down near the water, and at others at 

 the height of several hundred feet ; and it is a curious fact, 

 that the eggs, even of the same species, are always lighter in 

 the colour when placed high than when down near the level 

 of the sea. They disperse in winter, and range more in 

 breadth over the ocean. 



There are four species of skuas known as British birds, 

 tliough one of them is of rare occurrence; and these four 

 have not only the general appearance, but the gradations in 

 size, in the colours of the plumage, and in form, of the birds 

 of prey. Of the diurnal birds of prey, there is a regular gra- 

 dation from the golden eagle to the merlin ; and in the noc- 

 turnal ones, from the great-eared owl to the little owl. The 

 skuas feed by day, and thus the tints of their plumage re- 

 semble the diurnal accipitres more than the nocturnal ones. 

 The common skua has the same deep brown, and the same 

 unbroken colour as the eagle, and, like that bird, it has the 

 beak black. The others are light, and more or less marked 

 with spots on the under part ; and as their size diminishes,, 

 their wings and tails become proportionally more produced, 

 so that they have more the character of the hawks, and pos- 

 sess the means of more rapid and varied flight, but without 

 the same strength and daring. 



THE COMMON SKUA (Lestris catarractes). 



A figure of the common skua, on a scale of one-sixth of 

 the average dimensions, is given upon the plate at page 364. 

 It is there represented in the attitude which it assumes on 

 the water ; but, as is the case with birds of prey, it is seen to 

 greatest advantage when in pursuit on the wing. A bird in 

 motion is, however, a very difficult subject for an artist, 

 much more so than a quadruped; yet, even in these, the 

 expression of motion is not often well represented, though in 

 most species the artist has at least some advantage of the 



