262 SEA-BIRDS 



if not solely, in the fenlands draining to the Wash, in the Norfolk 

 and Suffolk broads, and in Romney Marsh in Kent. From all of these 

 places (fig 48, p. 265) it appears to have been driven by drainage 

 and reclamation. 



Its reappearance as a breeding-species in Britain was discovered 

 by R. Cooke (1946) at Pett Level near Winchelsea in Sussex, on an 

 area of a thousand acres that was submerged as part of the invasion 

 defences. On 10 June 1941 he found eight occupied nests on an 

 island formed by a collection of stranded debris. In 1942 five pairs 

 returned to the island, and young were safely hatched; but in 1943 

 only seven individuals arrived, were much disturbed by black-headed 

 gulls, and did not nest, and in 1944 the area was once more drained. 

 Since then no black tern has laid in Britain, though it would seem that 

 the broads and coastal marshes of Norfolk and Suffolk, now most 

 thoroughly administered as sanctuaries and for the preservation of 

 marshland habitats, are ready once more to provide the species with 

 a home. 



The sooty, noddy and bridled terns are more oceanic in their 

 habits, breeding on remote islands and reefs, and fishing far out at 

 sea. According to G. H. Wilkins (1923) sooties may feed as far as 200 

 miles from their breeding place. Their pelagic habit has caused differ- 

 ences in the routine of the breeding season; thus the incubation period 

 is shared in much longer shifts, according to Watson (1908): each 

 noddy tern sits for twenty-four hours, changing over at night; and 

 the incubating bird is fed by its mate. The clutch is normally only one 



The black skimmer [Rynchops nigra) is a black-backed red-footed 

 tern with specialised crepuscular feeding habits already described. 

 Rather clumsy and stupid at their breeding grounds, skimmers may 

 be persecuted by the nimble and powerful royal terns in search of 

 desirable nesting territory. The royal terns scratch for themselves a 

 home in the heart of the black skimmer colony, covering the skimmers' 

 eggs with sand or vigorously kicking them aside while the helpless 

 owners look on. Young skimmers are able to half-bury themselves 

 in sand by wriggling and scratching a hollow with a few vigorous 

 leg-movements. They show a "marked instinct of recognising parents' 

 raucous cries" (Bent, 1921). The peculiar long lower mandible is not 

 fully developed until the chick is able to fly. 



The nervousness of terns and their high excitability, higher than 

 that of the sociable gulls which are also subject to mass "alarms and 



