1909] Beebe: Birds of Northeastern Venezuela. 109 



Icterus chrysocephalus (Linn.). Moriche Oriole. 



We observed several specimens of this species flying about 

 La Brea and saw several in captivity hung outside the huts of 

 the Indians. The song is sweeter and more elaborate than that 

 of the troupial. 



Lampropsar tanagrinus guianensis (Cab.). Curly-headed 



Blackbird. 



Common in small flocks all along the Rio Guarapiche and the 

 Caiio Guanoco. Very tanager-like in actions and call-note. 

 They were feeding wholly on small insects. 



Part V. 

 Ecological Conclusions. 



We have a fair knowledge of the external appearance of all 

 the more important South American forms of bird life, although 

 there are doubtless scores of species still to be discovered. 



Of the ecology of the birds — in fact even the details of food 

 and nesting habits of many of the species we know little or 

 nothing. 



In the twenty days at our disposal no more than a superfi- 

 cial glance at the bird life of the coast of Venezuela was possible. 

 Many interesting facts came to our notice, however, and a few, 

 incomplete as they are, seem of sufficient interest for present 

 record. 



The tropics present nature at her extreme development, the 

 struggle for life is keener than elsewhere; the number of com- 

 peting species much greater than in cooler latitudes. Hence a 

 detailed study in this zone of adaptive radiation from the point 

 of view either of structure or habits, will ultimately prove of the 

 greatest value in throwing light on the processes of evolution. 



Among the birds observed by us in Venezuela were several 

 supposed to be peculiar to the Island of Trinidad, and Mr. Cher- 

 rie has taken one or two others far up the Orinoco. Owing to 

 the occasional strong wind storms on the Gulf of Paria and the 

 comparatively short distance between Trinidad and the main- 

 land — ^varying from eighty to only seven miles — the occurrence 

 of these insular forms at Guanoco is not remarkable. 



In the area of mangrove swamp and coastal forest which we 

 explored during the twenty days from March 25th to April 14th, 

 we positively identified 138 species of birds, of which 22 species 

 were breeding. This is between one-quarter and one-third, or 



