A CONTRIBUTION TO THE ECOLOGY OF THE 

 ADULT HOATZIN. 



Ecology of the Hoatzin. 



Part I — Introduction. 



Part II — History. 



Part III — Name. 



Part IV — Distribution. 



Part V — General Appearance. 



Part VI — Parasites. 



Part VII — Field Notes in Venezuela. 



Part VIII — Field Notes in British Guiana. 



Part IX — Food. 



Part X — Nest and Eggs. 



Part XI — Enemies. 



Part XII — Photographing Hoatzins. 



Part XIII— Odor. 



Part I — Introduction. 



The strangeness of life and structure of this bird have made 

 it classic in the annals of ornithology, and because of this claim 

 upon our interest I offer the present article as a resume of our 

 present knowledge of the habits of the adult Hoatzin. We are 

 still ignorant of a considerable part of its life history, although 

 there is small excuse for this, as the bird is sedentary, abundant 

 wherever found, and tarne to an absurd degree. 



I have had two brief opportunities for observing this species 

 in life, once in March, 1908, on the Guarapiche River in north- 

 eastern Venezuela, and again in April, 1909, on the Abary River, 

 British Guiana. On neither occasion were young birds to be 

 found, so my notes refer solely to the adults. 



Although i-t is not my intention to discuss the anatomy of 

 the Hoatzin, mention may be made of certain peculiarities, which 

 exert an important influence upon its habits and activities. 



The crop of this bird is unique in having assumed the struc- 

 ture and importance of the gizzard in other birds. It has in- 

 creased greatly in size, measuring, when well filled with food, 

 about two and a half inches in diameter. The walls, instead of 



