FOREST COMMUNITIES 427 



dad, only 5 are not arboreal, and 2 of these are aquatic; 14 52 of 66 

 mammalian species in central Borneo, 15 over half of the 161 species 

 in Sumatra, 16 and half of the 20 marsupials of New Guinea, are ar- 

 boreal. The insectivores as a group are largely aboreal in the tropics. 17 

 Monkeys and squirrels are characteristic forest animals; Siam has 

 26 and Borneo 31 species of the latter. 18 



The forest margin. — The depths of the forests are relatively poor 

 in animal life, much poorer than the open country. The forest margins, 

 which make a transition zone between the two, are richer than either. 

 Under these conditions the advantages of both communities are availa- 

 ble and their disadvantages are compensated. 19 The forest furnishes 

 a hiding place for terrestrial mammals during the day and a resting 



Fig. 117. — Deposition of eggs by Cochlostyla leucophthalma. After P. and F. 



Sarasin. 



place at night, while the neighboring grasslands supply food. In the 

 continuous primeval forests of the North Temperate Zone, such ani- 

 mals as the deer and the wolf are practically limited to a belt 5-8 km. 

 wide near the forest edge. 20 In Java, deer, wild boar, and leopard lie 

 concealed in thickets during the day and feed in the open at night. 21 

 The forests that border the African grasslands afford food and shelter 

 during the dry season for antelope, buffalo, rhinoceros, and elephants. 

 The flying foxes (Pterojms) sleep among the forest trees and fly out in 

 search of food. This is a common habit among birds which can range 

 far from their sleeping places in search of food. Isolated forest islands 

 in the Asiatic steppe are crowded with the nests of eagles, falcons, 

 rooks, and other birds which feed on the steppe. 22 



The forest is a refuge for man as it is for the other animals. The 

 camps of the American Indians were pitched along the forest mar- 

 gins. The more primitive peoples still seek shelter within the forests 

 from powerful. aggressors — witness the pygmies in Africa and Malay- 

 sia. 23, 24 The forest is not only a center of refuge from more powerful 



