SOME SUGGESTIONS FOR BIRD STUDY. 127 



scraped out by the cock in turning round, when showing 

 off to the female." (Saunders.) 



This is one of the most useful birds frequenting culti- 

 vated lands. Its food consists in great measure of " wire- 

 worms " and crane-fly larvae. 



BLACK-HEADED GULL (E.). This Gull is about 16 

 inches long. The back and wings are of a light slaty-grey 

 colour, the under parts white. In winter the head is 

 greyish, with a black crescent in front of the eye and a dark 

 grey patch behind it. In summer the head and throat are 

 deep sooty brown, the under parts rose-tinted. These 

 seasonal changes take place in the feathers themselves and 

 are not the result of moulting. The bill and feet 

 are red. 



This bird occurs along the shore, especially at estuaries, 

 and is common also inland, where it feeds abundantly on 

 crane fly, wireworni, and other insect diet, disposing of 

 enormous numbers of these agricultural pests. In spring 

 they frequent inland marshes, where they form " gulleries," 

 breeding in large companies. The nest consists of rushes 

 and sedges. The eggs, two or three, about two inches in 

 length, olive green to light brown with dark brown blotch- 

 ing. When the young are able to fly they migrate with 

 the old birds to the sea shore. 



THE SPARROW HAWK (E.). A bird of somewhat vary- 

 ing plumage, in general recognised by the marked length of 

 the foot (metatarsus), which is yellow in colour, the middle 

 toe long and slender, and by the lightish under parts barred 

 transversely with reddish brown. The upper parts are 

 bluish ; tail has from three to five dark bars ; the wings are 

 short. The cere is greenish yellow and the eyes orange. 

 The male is about 12 inches long, female, about 15 inches. 

 The Sparrow Hawk is widely distributed, nesting in trees, 

 building a nest of its own or in some cases utilising the 

 discarded nest of another bird, e.g. Wood Pigeon, adapting 

 it to its own purposes, especially when rearing its young. 

 The eggs, 4 to 6 in number, about 1 J inches long, pale blue, 

 almost white, blotched and smeared with reddish brown. 



