58 Zoologica: N. Y. Zoological Society. [I; 2 



Watching the Hoatzins carefully with our stereo glasses for 

 several evenings in succession, we came to know and distinguish 

 individual birds. Two, one of which has a broken feather in the 

 right wing, and the other a two-inch short central tail feather, 

 are excellent flyers, and, taking their flapping start from the 

 high branch, never fail to make their goal, going the whole dis- 

 tance, and alighting easily. All of the others have to rest and 

 one which is moulting a feather in each wing can achieve only 

 about ten yards. This one fell one evening into the water at 

 the second relay flight, and half flopped, half swam ashore. 



One evening a Hoatzin flew toward us and alighted near 

 some hens on the ground, but took wing almost instantly back 

 to his brush-wood. A day or two before we came, one of the 

 birds had used a beam of the porch as a perch. 



This general shifting occurs at both sunrise and sunset, and 

 is apparently always as thorough and noisy as we found it the 

 first evening of our stay. For months, we were told, it had been 

 kept up as regularly as clock-work. 



In the morning as the sun grows hotter, the birds become 

 more quiet and finally disappear, not to be seen or heard again 

 until afternoon. They spend the heat of the day sitting on their 

 nests, or perched on branches in the cooler, deeper recesses of 

 their linear jungle. 



The last view of them in the 'morning as the heat becomes 

 intense, or late in the evening, usually reveals them resting on 

 the branches in pairs close together. On moonlight nights, how- 

 ever, they are active and noisy, and come into the open to feed. 



The habit of crouching or squatting down on the perch is 

 very common with the Hoatzins, and it may be due to the weak- 

 ness of the feet and toes. I am inclined, however, to consider it 

 in connection with the general awkwardness in alighting and 

 climbing, as a hint of the inadaptability of the large feet to the 

 small size of the twigs and branches among which it lives. In- 

 explicable though it may appear, the Hoatzin — although evi- 

 dently unchanged in many respects through long epochs — is far 

 from being perfectly adapted to its present environment. It 

 has a severe struggle for existence, and the least increase of any 

 foe or the appearance of any new handicap would result in its 

 speedy extinction. 



Part IX — Food. 



The Hoatzin is unquestionably a vegetarian and the remains 

 of the previously mentioned four-eyed fish in the crop of one of 



