536 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1910. 



After they flop and clamber a few yards away from the canoe 

 they all quiet down, and with waving crests crane their necks at us 

 in curiosity from their perches. Each time they utter their grating 

 note they raise the tail and wings, spreading both widely. 



We had no opportunity of observing the quadrupedal habits of 

 the young hoatzins, but an interesting observation, first noted by 

 Mrs. Beebe, was that this finger or handlike use of the wing is present 

 in the adults as well. They never fly if they can help it, and even 

 when they pass over firm ground seem never to descend to it. But 

 their method of arboreal locomotion is to push and flop from branch 

 to branch. When the foliage and hanging vines are very thick they 

 use their wings, either together or alternately, to push aside the ob- 

 struction and to keep themselves from falling until a firm grip has 

 been obtained with the toes. This habit is extremely wearing on the 

 primary feathers, which become much frayed from friction against 

 stems and branches. 



I secured two specimens for the skin and the skeleton, respectively, 

 and found them in an interestingly irregular molt. In one (Coll. 

 No. 1138) the right third primary and the left fourth, seventh, and 

 tenth are about half grown. In the tail, the next to the outer pair 

 and the right central rectrices are in the same stage of growth, while 

 blood feathers are scattered here and there over the body. 



The second hoatzin examined (Coll. No. 1139) Avas in a still more 

 disheveled condition of plumage. Both wings and tail were badly 

 frayed and broken. Instead of the full number of 10 tail feathers 

 only 5 were present, 1 of which was half grown. Three blood-filled 

 sheaths just appearing above the surface of the skin represented the 

 remainder. In the right wing the second, eighth, eighteenth, nine- 

 teenth, and twentieth were considerably less than half grown. The 

 head, back, and thighs of this individual showed heavy molt, besides 

 many growing feathers over the rest of the body. 



The crops of these birds were distended with a finel}^ comminuted 

 mass of bright green vegetable matter, the leaves of the mangroves 

 and some other river growths. 



In one crop, scales and the remains of a small fish were also present, 

 and as we once saw a hoatzin with dripping plumage, creeping from 

 the water up a slanting mangrove root, it may be that the adult birds 

 retain some of the natatory skill which characterizes the nestlings. 

 This, however, is mere conjecture. The scales in this instance were 

 those of the little four-eyed fish {Aiiahleps anableps) so common 

 about the muddy shores of the Caiios. 



FIELD NOTES IN BRITISH GUIANA. 



On April 12, 1909, Mrs. Beebe and I reached a bungalow used as 

 the headquarters of a rice plantation, some 20 miles up the Abary 



