AISflMAL BEHAVIOR — WALKER 277 



is at a new. point of rest. This is a valuable accomplishment to many 

 little creatures whose chief danger usually lies in attacks from pred- 

 ators such as snakes, cats, weasels, owls, hawks, or other creatures that 

 strike or grab with lightninglike rapidity. Therefore, if at the first 

 instant of alarm the intended victim changes his first location to some 

 other he will probably be safer than before ; and if he follows this up 

 with further prompt get-aw^ays, he will frequently avoid capture. 



I have observed that small mammals are much disturbed by the 

 rattling or crumpling of paper or cellophane. If this sound is con- 

 tinued they soon become nervous and seek shelter. I have no proof 

 as to why they react in this manner, but I feel certain that it is 

 because the rattling and crackling of paper reminds them of the 

 sound of enemy footfalls on dry leaves. 



Gibbons (HyJohates and Symphalangus) are the most agile acro- 

 bats among the primates. They literally fly through the trees in 

 great swings with their long arms, and they are so thoroughly at 

 home in the treetops that they have little to fear from enemies. But 

 they are not so free from danger when they are on the ground, which 

 consequently they are loath even to touch. When they drink from 

 the pools or streams, they prefer to hang by an arm and a leg from 

 a branch or vine, merely dipping the somewhat folded hand into the 

 water and raising it to the upturned mouth. This method of drink- 

 ing can be frequently observed in a zoo. Gibbons are also adept in 

 eating oranges. Instead of making a messy job of it as many animals 

 do, they will, if given sections of an orange carry them to their 

 mouths in their hands and direct their mouth upward so that scarcely 

 a drop of the juice is lost. In their native haunts they are accus- 

 tomed to eating many kinds of juicy fruits. 



The gerenuk (Litocranius) is an African antelope of extremely tall 

 and slender build much like the giraffe in form but standing only 

 about 3 feet high at the shoulders and perhaps 5 feet high to the 

 top of the head. This little creature inhabits a region of very sparse 

 vegetation where concealment would ordinarily be difficult. It has 

 apparently learned that it can best escape from its enemies by lying 

 down flat on the ground. A young one that was perhaps one-third 

 grown when it was first placed in its cage amid strange surroundings 

 in the National Zoological Park at once took this position. 



Tlie giant eland (Taurotragits) which is almost as large as a 

 horse and inhabits the barren plains of Central and South Africa 

 has a similar habit of lying flat on the bare ground. 



Innumerable other instances might be mentioned of the methods 

 used by animals in looking out for their own welfare. There might 

 be cited and discussed at length the manner in which animals re- 

 main motionless and by their color pattern blend with their sur- 



