THAYER AND BANGS : PEARL ISLANDS BIRDS. 



143 



From these measurements it can be seen at a glance that the Pearl Islands 

 Green Heron does not differ in size or proportions from birds from the West 

 Indies and continental tropical America. There is a considerable individual 

 variation in size in the Green Heron everywhere, but averages show that 

 B. virexcens maculata is easily separable from B. virescens virescens of eastern 

 North America on account of its smaller size. 



After examining a very large amount of material in this connection, we 

 are forced to place very little reliance on color as a character by which to dis- 

 tinguish the various races of this species. Seasonal difference in this respect is 

 very great, individual variation is also great, and in arid regions the bird 

 bleaches out very fast. Mr. J. H. Riley in a recent publication ^ has stated : 

 " Green herons from the West Indies, except the Bahamas, are smaller, have 

 the crest more plumbeous, and the white edgings to the wing coverts are less 

 pronounced and not so tawny in color when compared w-ilh Florida specimens." 

 We cannot find a single one of these color characters stable, and furthermore 

 are unable to separate Bahaman birds from those from other West Indian 

 Islands killed at corresponding dates. Bahaman birds appear to bleach out 

 and become very pale in summer, but so do birds in Barbados and Bequia, and 



1 Catalogue of a Collection of Birds from Barbuda and Antigua, B. W. I., 

 Smith. Misc. Collections, vol. 47. 



