STRUCTURE AND SEA-BIRDS OF THE N. ATLANTIC II 



and an extensive continental shelf, especially off Yucatan. Breeding 

 sea-birds are scarce, except terns and the ubiquitous bigua cormorant, 

 which is as much a fresh-water as a salt-water bird. The Sandwich 

 tern, which is known as Cabot's tern in North America, breeds in 

 several parts of the Gulf coast of Mexico, which is more suited for 

 terns than for any other sea-birds. On the grassy islands among the 

 lagoons and marshes of the Texas coast, the gull-billed tern and 

 Forster's tern Sterna forsteri, are found. The beautiful Caspian tern 

 Hydroprogne caspia, also nests in a few places on sandy islands, and 

 there is an interesting outpost breeding-station of the white pelican 

 Pelecanus erythrorkynchos, on the Laguna de la Madre, south of Corpus 

 Christi, near the Border. The rest of the population of this fine bird 

 is found in western North America. 



Along the Louisiana coast, where there are many protected reserva- 

 tions, there are very big colonies of the laughing gull Larus atricilla, 

 especially in the marshy islands of the Mississippi delta, which are 

 overgrown with grass and low mangroves. One of the reservations 

 is in the Breton Islands, 114 miles off the main Louisiana coast. 

 Here are great colonies of terns on low flat sandy spits, including 

 Caspian, Cabot's and royal Thalasseus maximus (Bent 192 1). Forster's 

 and common terns Sterna hirundo, also nest in the Breton Islands" as 

 do numbers of the extraordinary black skimmer, an aberrant tern 

 whose lower mandible is prolonged and with which it scoops food 

 from the surface of the sea. The peninsula of Florida has to its west an 

 immense continental shelf, along the lower end of which is a famous 

 chain of Keys. Beyond Key West, at the terminus of the Key railway, 

 many miles to sea, lie the dry Tortugas, flat islands of coral, their 

 surface, largely of coral sand, clothed in parts with dense cactus as 

 well as with bay cedar, with many bare and grassy spaces between. 

 On the cedars and the cactus immense numbers of noddy terns nest: 

 often over the nests of the sooty terns on the ground below. 



The Florida coast has one of the best stations in the U.S.A. for the 

 roseate tern. The darter, which most North Americans allude to as 

 the water-turkey (it is a fresh water lover), and the double-crested 

 cormorant of Florida, commonly nest in trees in many swampy places 

 along the coast. Brown pelicans nest by lagoons and in mangrove- 

 keys on both sides of the peninsula. 



Naturalists accustomed to British coast conditions can have little 

 notion of the interminability of the low-lying eastern coast of North 

 America. Indeed, on the entire stretch of mainland coast from Southern 



