300 THE NESTS AND EGGS OF 



of the &^^. Average measurement, 2'0 inches in length, 

 by I '4 inch in breadth. The duration of the period of 

 incubation is unknown, as is also the sex which performs 

 the task. 



Diagnostic characters: The eggs of this Tern 

 cannot readily be confused with those of any other 

 " British" species, but I am not prepared to say whether 

 they can be distinguished from those of allied birds. 



Family LARTD.-E. Genus Sterna. 



Sub-family STERNlNAi. 



SOOTY TERN. 



Sterna fuliginosa, Gmeli7i. 



(British : Very rare abnormal spring (?) and autumn migrant.) 



Double Brooded (?), Laying season, September to January (South- 

 ern Hemisphere), April and May (Northern Hemisphere). 



Breeding area: Oceanic tropical zone. The Sooty 

 Tern, like the Noddy, breeds on the various islands that 

 dot the tropic seas right round the world. Amongst its 

 principal breeding places may be mentioned the islands 

 off the coast of Florida, the West Indies, the island of 

 Ascension, St. Helena, Madagascar, Rodriguez, Mauri- 

 tius, the Chagos Archipelago, the Laccadives, the islands 

 in the Red Sea and Persian Gulf, Ceylon, many parts of 

 the Malay Archipelago, the coasts of Australia, various 

 islands throughout Polynesia, and in Lower California. 



Breeding habits: The Sooty Tern visits its various 

 breeding places for purposes of reproduction in May 

 and September, according to locality and latitude. It 

 is a gregarious species, some of its colonies being very 

 extensive, but of its pairing habits nothing appears to 



