364 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1953 



tumbling out of a palm tree fully 30 feet above the ground. Each 

 sloth had a firm grip on the other with its hind feet and it was quite 

 apparent they had been fighting and had become so occupied that 

 they had forgotten gravity was still an active factor of their environ- 

 ment. A few seconds later they began to recover from their fall. 

 They let go their holds and wobbled and rolled awkwardly over the 

 ground to the nearest lianas which they slowly began to climb. We 

 needed pictures of a sloth so one was captured with a loop on a pole 

 and was carried out to a clearing a half mile away where there was 

 sufficient light for photography. The grayish green of their coarse 

 hair and their slow method of locomotion on the under side of limbs 

 make them difficult to find even where they are plentiful. The green- 

 ish color is the result of an alga growing on the hairs. There are 

 also three species of moths and one beetle that are almost always 

 found darting in and out of the coarse pelage. Whether the larvae 

 of these insects eat the alga, the hairs, or the tiny sloughed-off bits 

 of epidermis appears to be another problem of interrelationships in 

 the intricate web of this tropical forest community that needs to be 

 investigated much more thoroughly. 



A mammal that seems to be equally at home in either arboreal or 

 terrestrial environments is the three-toed anteater or tamandua 

 (pi. 2, fig. 2). Its long prehensile tail enables it to use tree routes 

 of travel and to work on insect nests far above the ground. With 

 the powerful claws on its front feet it can open the hard, tough ant 

 and termite nests without difficulty. Its most striking adaptation, 

 however, is its long wormlike tongue that can be extended from the 

 mouth 5 inches or more to extract insects out of the intricate and 

 interlacing system of tubes found in termite and ant nests. While 

 raiding a nest of termites or ants a tamandua would soon become 

 covered with biting or stinging insects were it not for the way it 

 uses the claws on its hind feet. These claws are arranged along the 

 foot in the form of a comb with which the anteater keeps its pelage 

 relatively free of insects by combing almost constantly with its hind 

 feet as it continues to feed. 



There are many strictly terrestrial mammals but none is more fre- 

 quently seen in the forest than the agouti (pi. 3, fig. 1) or neque as it 

 is called by the Panamanians who prize its flesh as a table delicacy. 

 The agouti belongs to a group of South American-type rodents that 

 have moved up through Central America since the Ice Age. It is 

 commonly seen in daytime eating the fallen fruits of various forest 

 trees and when surprised squeals loudly and dashes off to its burrow. 

 No doubt the agouti provides much food for jaguars, piunas, and 

 ocelots. 



Near the laboratory at the edge of the forest is a breadfruit tree 

 which was introduced long ago. One evening we watched a pack 



