BIRDS OF THE BRITISH ISLES. 375 



Common Gern* 



THE Common Tern (Sterna hirundo, Linnaeus) is one of 

 our summer visitors to the British Isles, and is found in 

 most parts of the Palearctic Region, as well as the eastern 

 portions of North America. The adult in nuptial plumage 

 has the mantle and wings pearl-grey; crown and nape, 

 black; rump and tail, white, longest tail-feathers, grey on 

 outer margins ; under parts, greyish on breast and belly ; 

 irides, dark brown ; bill and legs, deep orange red, blending 

 on the former into blackish towards the tip. Length, from 

 thirteen to fifteen inches. The female is similar to the 

 male. The young have the crown and nape mottled with 

 brownish ; the mantle is mottled with greyish. This tern 

 can readily be distinguished from Sterna Arctica by its 

 longer tarsi. 



