294 ANiNTUAL REPORT SMITHSONIAN INSTITUTION, 1940 



each other, they utter a little buzzing growl. Also I noticed that a 

 single one will give the same sort of a call when it is in the immediate 

 presence of a grasshopper mouse, its mortal enemy in the wild. I 

 have heard my pet kangaroo rat utter chirps that could be heard at 

 a distance of 8 or 10 feet. If one of these animals is held close to 

 one's ear a series of buzzing notes can be heard — dots and dashes in 

 varying frequency and tempo — that must mean something to the 

 creature that makes them. In their deep underground dens a distinct 

 tapping of feet or tails can be heard from outside. These sounds 

 evidently serve as means of communication between different nest 

 chambers within the elaborate dwelling. 



My pet grasshopper mouse calls, apparently to attract attention. 

 These signals are most noticeable when the animal is running at 

 liberty on my desk and my wife and I are in an adjoining room. 

 At such times, he will choose a location from which he can watch 

 us, then, rising on his hind legs, he will give an exceedingly high 

 pitched piercing squeak that may be likened to a very high-pitched 

 automobile brake squeak. The sound is of about one second dura- 

 tion. If I am about my desk he gives the call much less frequently, 

 unless I appear to be paying no attention to him. The loudest of 

 his calls can be heard by the ordinary human ear at a distance of 

 perhaps 40 to 50 feet; but I have often seen him go through the 

 motions of giving the call when the sound was so faint or high pitched 

 that I could not hear it even when I was not more than 2 to 4 feet 

 away from him. 



Giraffes {C amelopardalis) are commonly thought to be voiceless. 

 It has even been claimed that they possess no vocal cords. However, 

 anatomists now say that fliey do possess poorly developed vocal 

 cords; and there are authentic records that giraffes under extreme 

 excitement utter a bleating call. 



The emperor penguin {Aptenodytes forsteri)^ an Antarctic sea 

 bird that was brought to the National Zoological Park in February 

 3940 from the United States Antarctic Exploration Expedition, 

 greeted visitors in his cage by approaching them with his slow 

 waddle. AVlien about 5 or 6 feet away he would stop, bend his head 

 far down on his breast and raise it gradually while he uttered a series 

 of guttural musical notes somewhat like the cackle of a hen in point 

 of timing but far deeper and more pleasing in quality. It appeal's 

 probable that since the emperor penguin has practically no enemies 

 on land or ice, he considers any other large object that approaches 

 him as friendly. The emperor which stands about 40 inches high 

 to the top of the head, is the tallest of the inhabitants of the 

 Antarctic ice barrier. 



