TERNS 53 



strikingly coloured beak, and the deep orange legs. Sexes 

 alike. In summer the fore-part of 

 the beak is red, the hinder-part slate- 

 blue, the two areas being divided by a 

 yellow line. In winter the yellow 

 line and the slate-blue horny plate 

 disappear, together with the cream- 

 coloured fillet at the base of the bill, 

 the orange-yellow rosette at the 

 gape, and the slate-coloured append- 

 ages above and below the eye. No 

 noticeable seasonal change in the 

 plumage. Upper-parts black. Sides of the head pale greyish. 

 Under-parts white, except black band round under the throat. 

 The young have the beak much smaller. 



Nest. In a burrow in the soil on the top or sides of an isle 

 or cliff, also under boulders and in crevices. Material : usually 

 a little grass and feathers. Species breeds in colonies. 



Eggs. One. Dirty white, with more or less faintly marked 

 shades of brown or violet. Av. size, 2-39x1 '67. Laying 

 begins in May. One brood. 



(3) Family: Laridce. (a) Subfamily: Sternince Terns 



105. Sandwich-tern [Sterna sandvicensis sandvicensis Latham ; 

 Sterna cantiaca Gmelin]. Summer visitor to our coasts. Local. 

 Bird of passage. 



Bird. Length 16'5 in. The Terns are sometimes called sea- 

 swallows owing to their general re- 

 semblance to the swallow tribe in 

 appearance, allowance being made for 

 the much larger size and the grey 

 coloration. The present form may be 

 distinguished from the following by 

 its black relatively long beak with j,. * 



yellow tip, black legs, and the striking 

 velvety black mane-shaped crest and its habit of nesting in 

 close packs. In flight its stouter build, longer beak and 

 shorter tail aid recognition ; also its distinctive note a sharp 

 Kirr-whit. Top of head and nape black. Upper-parts and wings 

 mostly pearl-grey, but rump and tail white. Under-parts white 

 with a not very apparent salmon-pink tinge. The young show 

 black or dusky markings on the upper-parts. 



Nest. Place: usually near the sea on sand among marram 

 grass and the like, in shingle, also on mud-banks. The nest 

 scrape is either unlined or more or less lined with grass and odds 

 and ends picked up on the shore. Species breeds in colonies. 



