328 Annals of the Carnegie Museum. 



bnla, Dendroica coronata, the swallows, Botaurus lentiginoses, the 

 ducks, and some of the shore-birds. 



This peculiarity makes collecting them very difficult, especially the 

 warblers and thrushes, which may be common enough high up in the 

 tree-tops or hidden away in the thick forests, but which rarely come 

 out into the open, except such species as Dendroica (estiva, D. pen- 

 sylvanica, Wilsonia pusilla, and Setop/iaga ruticilla. 



General Notes on the Habits of the Resident Species. 



Taken as a whole the birds belonging to, or offshoots of, the Sonoran 

 fauna do not differ very materially from those farther north, with re- 

 spect to their habits, food, song, breeding, etc. It is chiefly among 

 the representatives of the Tropical fauna that peculiar forms are to be 

 met, and where specialization has been carried to a remarkable extent 

 in some species and genera. Many species are never to be found out- 

 side of the dark, wet jungles of the Caribbean lowlands, or the chilly, 

 rain-soaked mountain-slopes. Some never leave the ground, except 

 for a low short flight when suddenly flushed ; while others never seem 

 to go near the ground. With the exception of the wrens, few birds 

 belonging to the Tropical fauna are endowed with the power of song. 

 It is true that some have a pleasing, musical call, but they are not 

 songsters, while the great bulk of the Dendrocolaptidce, Trogonidce, 

 Pipridce, Cotingidce, Trochilidoz, Ramphastidce, Momotidce, Galbulidce 

 are not only without song, but many scarcely even chirp, or. if so, in 

 a harsh discordant key. It is also noticeable that the vocal powers 

 decrease in about the same ratio as the plumage increases in brilliancy, 

 of which type the trogons are good examples. 



Contrary to the usual impression, birds inhabiting the impenetrable 

 jungles, where perhaps many never see a human being in the course of 

 their lives, are extremely shy and hard to approach, while those found 

 in the settled districts and near the haunts of man are quite indifferent 

 to his presence. Thus it would seem that fear in birds is inspired by 

 things which they have not been accustomed to seeing rather than 

 by those things which we would naturally suppose would be a fear- 

 inspiring object to them. Sudden movement or sharp sounds will also 

 frighten most birds more than the mere quiet presence of an unaccus- 

 tomed object, and, after being frightened away precipitately by the sud- 

 den noisy approach of the collector, they will stealthily return to have 

 a look at the curious object, should he remain perfectly quiet. Often 



