12 SEA-BIRDS 



Mexico to Maine, about four thousand miles, there is not a single cliff, 

 nor indeed a mountain coming down to the sea. All through Florida, 

 Georgia, the Carolinas, Virginia and Maryland to the New England 

 States, runs a complex of lowland and shallow shores, broken in places 

 by inlets such as those of Chesapeake and Delaware Bays and Long 

 Island Sound. This is a tern coast. In the northern parts the effect 

 of the Labrador current is felt and there is a fairly steep decline in 

 temperature, which is why such tropical forms as the brown pelican 

 and Florida double-crested cormorant drop out of the community 

 in South Carolina. One tropical species which is distributed all along 

 this coast, however, is the laughing gull ; and the gull-billed tern reaches 

 north to Virginia. Rather oddly, two terns, the common tern and 

 Forster's tern, appear to avoid the mainland coast from Florida to 

 South Carolina, though they breed to the west and north of it. 



The distribution of tern populations on this Atlantic coast has had 

 a chequered history, and is dealt with in some detail in the chapter 

 on Sea-Bird Populations (Chapter 3, p. 85). 



In the New England States and Maine we encounter the first 

 truly northern elements in the Atlantic sea-bird fauna, and a com- 

 munity of sea-birds which is intensively watched and studied, as is 

 the very similar community on the eastern side of the Atlantic, ten 

 degrees farther north. We now meet not only some of the terns but 

 some of the gulls that breed in the British Isles. In Maine and New 

 Brunswick, where little cliffs begin and the wooded coast closely 

 resembles the skerry-guard of Stockholm, and other parts of the 

 Baltic archipelago, we find the southernmost auks — black guillemots 

 Cepphus grylle, puffins Fratercula arctica, and perhaps still a pair or two 

 of razorbills Alca torda. We even find tubenoses breeding in Maine, 

 birds which we had last encountered in the Caribbean Antilles. 

 (Apart from Audubon's shearwater and the rare diablotin (p. 76), 

 which nest in various of the Antilles, no breeding petrel is found in the 

 western North Atlantic south of Maine, save on Bermuda.) 



The rocks and coral reefs of Bermuda, which is 580 miles from 

 Cape Hatteras, the nearest point on the United States mainland, 

 support an interesting little community of sea-birds, which consists of 

 the northernmost outposts of the breeding population of an otherwise 

 completely tropical species, the white-tailed tropic bird Phaethon 

 lepturuSi besides the common tern, the roseate tern, possibly the Manx 

 shearwater Puffinus puffinus, Audubon's shearwater, and the cahow 

 Pterodroma cahow ^ thought to be extinct for many years. 



