ON MOORS, COMMONS, AND HEATHS. 157 



may also be found commonly distributed in many 

 of the more northern moorland districts during 

 summer, breeding in all suitable localities ; but 

 we shall meet with this species in our ramble 

 over the Broads, and therefore reserve our 

 observations on its nesting economy until then 

 (see p. 192). 



Whilst on these Highland moors a passing 

 notice of the Skua Gulls is necessary. Two 

 species breed upon them. The most commonly 

 distributed of these is RICHARDSON'S SKUA Northern 



/ . T j -\ T Scotland and 



(^tercoranus nc/iarasom). It is a summer adjacent 



V . . . , , ; , . , , . isles. 



visitor to our islands, reaching its breeding- Hebrides, 

 grounds at the end of April or beginning of May ; 

 and its nests are scattered up and down the 

 moors, sometimes near the sea, at others a con- 

 siderable distance from the coast. These nests 

 are mere hollows lined with a few scraps of 

 withered herbage, and made with little or no 

 attempt at concealment. The two eggs are 

 olive or reddish brown, spotted, blotched, and 

 streaked with dark brown and gray. Richardson's 

 Skua is distinguished by its smaller size, narrow 

 pointed central tail feathers, and white shafts to 

 the primaries. A light and dark race of this 

 bird is found, and both of these forms interbreed 

 even in the British Islands, the offspring instead 

 of being intermediate in colour between the two 

 extremes, taking the character of one or the other 

 parent. The dark form is almost uniform sooty 

 brown in colour ; the light form has the upper 

 parts slate-gray, the underparts white, including 

 the sides of the neck nearly to the nape, which 

 are suffused with yellow. The other species, 



