284 THE NESTS AND EGGS OF BRITISH BIRDS. 



breeding-haunts of this Skua are wild open moorlands 

 at no great distance from the sea — vast expanses of 

 heath, and rank grass and moss, broken up into marshes 

 and studded with pools. It is more or less social during 

 the summer, but does not breed exactly in colonies, 

 although many pairs may be scattered over the moors 

 in one locality. It appears to pair annually. The nest 

 is invariably made on the ground, with little or no 

 attempt at concealment. It is merely a hollow, lined 

 with a little dry grass or other withered herbage ; and 

 in some cases is nothing but a depression in the moss. 

 The bird sits lightly, leaving the eggs as soon as the 

 breeding-ground is invaded by man, and flying to and 

 fro, sometimes swooping within a few inches of his head, 

 and frequently betraying their whereabouts by too much 

 anxiety for their safety. If care be taken not to alarm 

 the bird more, it usually soon settles on the ground 

 again, and eventually returns to the nest. 



Range of egg colouration and measurement: 

 The eggs of Richardson's Skua normally are two in 

 number, but instances of three having been found in one 

 nest are on record, whilst occasionally only one is found. 

 They vary considerably in shape, some being very 

 pyriform and pointed, others more rotund. They vary 

 in ground colour from olive to brown of various shades, 

 spotted and speckled with very dark brown, and with 

 a few obscure underlying markings of grayish-brown. 

 Some varieties have many of the spots more or less 

 elongated into comma -shaped marks, or irregular 

 masses ; others have most of the markings congregated 

 in a zone round the larger end of the (tg^ ; more gener- 

 ally they are pretty evenly distributed over the entire 

 surface. Average measurenient, 2"3 inches in length, 

 by I '6 inch in breadth. Incubation, performed by the 

 female, lasts about a month. 



