434 LAND ANIMALS 



a primitive agriculture. The scarcity of mammals in the forest appears 

 greater than it actually is, because, with the exception of apes and 

 squirrels, the majority are nocturnal and hide during the day. Thus 

 one may wander for months in the Cameroons without seeing a single 

 wild boar, although the tracks show that these animals are constantly 

 about. 45 The same is true for forest antelopes of Africa and for the 

 tapir in America. 



The South African wild boar is an important animal of the wooded 

 regions; it extends out of the tropical rain-forests proper into other 

 forests; moist forests are occupied whether montane or lower lying, 

 high crown forests, particularly if water and ferns are present. The 

 animals go about in droves and can defend themselves well. They 

 are nocturnal and follow trails made by elephants, getting food from 

 the faeces of the latter and from roots and trees which the elephants 

 have dislodged. Baboons follow the wild pigs and obtain scorpions, 

 earthworms, and insects which the pigs have turned up, as well as 

 eating roots and the like which they have missed. 



The pigs root up the soil to a depth of several inches, eating 

 buried seeds, roots, rhizomes of ferns, and insects but not much bark 

 or foliage. They take also fruits of forest trees, the seeds of some of 

 which resist digestion and are scattered. Although there are large 

 numbers in favorable forests and they are dependent on the forest 

 for food, yet the damage done is negligible and is more than offset 

 by their work in improving the seed bed, and in keeping insects in 

 check. 46 



As in other groups, the majority of the mammals of the tropical 

 rain-forest are arboreal animals that seldom set foot on the ground, 

 and must therefore be relatively small. One thinks of monkeys as the 

 predominant arboreal mammal of such regions, yet, at least in Old 

 World forests, the squirrels supply a greater number of species. The 

 social habits and noise of the monkey hordes make them noticeable 

 to the ear, though not all with such vehemence as the howling 

 monkeys (Alouatta) of America, whose bull-like bellowing fills the 

 forest at sunset or when awakened by a passing airplane. The ma- 

 jority of monkey species belong to the warmer forests of the world, 

 and, like other arboreal animals, they are structurally adapted to 

 arboreal life. Many are frugivorous and emigrate, as do the birds, 

 from fruit tree to fruit tree, though the forest canopy. 47 The American 

 monkeys differ markedly from those of the Old World. They belong 

 to separate suborders divided by such fundamental structural char- 

 acters as dentition and such fundamental habits as the use or failure 

 to use the tail as a prehensile organ. Other arboreal mammals in 



