cherrie;: ornithology of the; Orinoco re;gion. 359 



were found there May 25th and eggs June nth. From the 15th to 

 the 25th of June the laying season at Caicara was at its height and 

 the river was rapidly nearing high water mark. 



Basing my conclusions on the condition of the ovaries in the 

 birds taken at Bolivar, early in April, I returned to that locality the 

 first week in July, expecting to find young Hoatzin. What was my 

 surprise to find the Bolivar birds nest building — no young; and onlv 

 one set of eggs taken July 4th. The colony that I had been observing 

 at Bolivar made their home in the thick tajigle of tree tops bordering 

 a small lake which occupies a natural basin in an extensive area of 

 low land separated from the river by high rocky embankments. The 

 rapidly rising waters of the Orinoco did not break over this embank- 

 ment until June 20th. The Hoatzin apparently had not commenced 

 serious nesting until after that date ! Did they deliberately await the 

 rising of the water? 



The nest of the Hoatzin is a slight platform of dead twigs, 

 loosely put together, out towards the tips of long slender branches, 

 and frequently with but very frail support. Sometimes the nests are 

 almost concealed by surrounding leaves, again they are placed in dead 

 or leafless trees where surrounding foliage does not offer any con- 

 cealment. If the nest is high enough the eggs usually can be seen 

 from below through the nest walls. 



The young* Hoatzin is almost naked at birth and a shiny jet 

 black, with olive wash, in color. Within a day or two their eyes 

 are wide open and if a nest be approached without extreme caution 

 it will be found empty. But a little quiet patience will probably 

 reward the collector — at the end of a few minutes the young will be 

 seen making their way from out of the water, into which they had 

 deliberately dropped ; along and over the limbs back to the nest. 

 Their locomotion at this time is effected by the aid of the bill, the feet, 

 and the claws that in the young are found on the end of the thumbs 

 and index fingers. 



In a series of thirteen sets of eggs, a considerable variation in 

 size, shape, and markings is noticeable. The general shape is ovate, 

 varying from a rather long ovate to short ovate, and occasionally 

 there is an approach toward the oval. (The two eggs of set No. 

 13898 Cherrie Collection are almost perfectly oval). The general 

 color is a pinkish cream color, varying considerably in shade in the 

 various sets, the marking's consist of dots, spots and splashes, scat- 



