Vol. 5, p. 197-202. June 7, 1926. 



Occasional Papers 



OF THE 



Boston Society of Natural History. 



A REVIEW OF THE RACES OF ELAENIA MARTINICA (LINNE). 



BY JAMES L. PETERS. 



During trips to the West Indies in the interests of the Museum 

 of Comparative Zoology in the winters of 1917, 1922, and 1925, 

 I have endeavored to collect as large series of Elaenia martinica 

 as possible from the islands visited, with a view to determining the 

 number of forms into which this species divides, and their dis- 

 tribution. This material now totals about 70 skins from St. 

 Thomas, Tortola, Virgin Gorda, Anegada, Anguilla, St. Eustatius, 

 St. Kitts, Nevis, Martinique, St. Lucia, and St. Vincent; and it is 

 supplemented by examples in the Museum from Antigua, Guade- 

 loupe, Dominica, St. Lucia, St. Vincent, Mustique, Barbados, 

 the Caymans, and Old Providence. Material representing the 

 following islands has been borrowed from the Biological Survey 

 and the U. S. National Museum: Vieques, Culebra, Old Provi- 

 dence, Cozumel, and Mujeres. I am under obligations to the 

 authorities of the Field Museum for the loan of necessary material 

 from Aruba, Bonaire, Curagao, and St. Andrews. 



There are several factors to be borne in mind when working 

 with Elaenias and particularly with the present species. In the 

 first place, the colors seem to change gradually with the age of 

 the specimen; secondly, some bleaching occurs in life; thirdly, 

 martinica has two color phases, one in which gray predominates, 

 and another in which the posterior under parts are strongly 

 washed with yellowish and the upper parts with olive; fourthly, 

 martinica exhibits a considerable range of individual variation in 

 size. The occurrence of birds of varying size and color side by 

 side on the same island gives the field impression of two forms 

 occurring together; but museum examination shows that these 

 differences cannot be correlated in any way with age, sex, or 

 locality. 



Elaenia flavogastra'^ occurs on St. Vincent side by side with 

 E. martinica, but the two are very distinct species, differing in 

 certain external structural modifications. Flavogastra is readily 

 distinguished from martinica by the more triangular shape of the 

 bill and shorter wing tip (the longest primaries exceeding the 

 secondaries by 10 to 14 mm.). The Yellow-belHed Elaenia {E. 

 flavogastra) of the southern Lesser Antilles has received a variety 

 of treatment at the hands of various authors. Clark (Proc. Boston 

 Soc. Nat. Hist., vol. 32, no. 7, 1905, p. 79-80) and Ridgway 

 (Birds No. and Mid. Am., part 4, 1907, p. 425) both regard it as 



1 Pipra flavogaster Thunberg, Mem. Acad. Imp. St. Petersburg, vol. 8, 1822, 

 p. 286 (Brazil). 



JUN 15 192 G 



