GORILLAS— PITMAN 269 



few minutes previously — if only they would come out again — and, 

 about 60 paces distant, violently agitated bushes and cover, with an 

 occasional glimpse of a black shaggy body or a long hairy arm. Once 

 there was a good view of a female as she swung down from a small 

 tree beside a large bush. Dropping lightly to the ground, she> 

 offered a perfect facing view, one long arm momentarily upright 

 grasping a stout branch. Others were seen at various times high 

 up the smaller trees; in this respect my very limited experience 

 suggests that the big male is more enterprising than his wives and 

 children. 



After the troop had become aware of our presence, and when it 

 seemed quite hopeless to expect a chance to secure a photograph, 

 the party retraced its steps up the hill, making a slight detour to 

 follow a shoulder instead of forcing its way through a tangled 

 reentrant. To our amazement the gorilla females and youngsters 

 were observed a little below and parallel to our line of direction 

 inquisitively creeping up the reentrant, and having a good stare at 

 us by parting the undergrowth and peeping through as opportunity 

 offered. 



This boldness revived the idea of a photograph, but it was no 

 good, the gorillas knew all about us and had no intention of exposing 

 themselves unduly, and as soon as we began to descend again they 

 vanished like a party of ghosts and were heard and seen no more. 

 The most satisfactory feature of the whole episode is the fact that 

 the gorillas were not unduly disturbed, and just faded away quietly. 

 The preference for feeding in the vicinity of the valley bottoms is 

 explained by the occurrence of more luxuriant vegetation induced 

 by additional humidity. 



The wrathful roar, sometimes aptly described as a hellish challenge, 

 of the angered male is evidently a rarity in the Kayonsa region. 

 In 18 months my prospector informant had never heard it, and the 

 local natives — usually loquacious on such matters — did not appear 

 to be impressed by any outstanding yell. 



There are many gorilla noises, the one most frequently described 

 by writers being the peculiar drumming of the chest. It is most 

 certainly done as a challenge and not necessarily to frighten, and is 

 by no means confined to demonstrating males, as is often claimed. 

 It is a sound which carries a long distance, especially across a valley. 

 The young males practice it at an early age, and Mok, directly after 

 his arrival at Regent's Park, used to jump up suddenly from what- 

 ever he was doing and rush wildly round his cage bellowing and 

 frantically beating his chest. The partially cupped hands, and the 

 way in which they are held and strike the chest, are responsible for 

 the penetrating nature of the sound. 



