264 THE FAUNA OF BRITISH EAST AFRICA part iii 



zebra, as well as the numerous species of antelope ; and few scenes 

 leave a deeper impression on the imagination of the traveller 

 than the great herds of game, gambolling and feeding on the 

 vast plains of the interior. 



The relative importance of the great mammals is increased 

 by the scarcity of the small ones. This reminds us at once of 

 Darwin's famous comparison of the mammalian faunas of 

 Africa and South America, when he pointed out that the 

 barren steppes of the former are inhabited by vast herds of 

 enormous animals, whereas the luxuriant vegetation of the 

 latter supports only a few small forms. Darwin's statement of 

 the facts is undoubtedly correct, and his conclusions just and 

 instructive, but he gave no explanation of the anomaly. This 

 may be suggested by describing Africa as the land of migratory 

 mammals, instead of that of large mammals. The rains fall at 

 two special periods of the year, which differ in different parts of the 

 country, and at other times the steppes are burnt and foodless. 

 In the dry season the soil is baked into ferruginous brick-like 

 loam, so intensely hard that small mammals cannot burrow into 

 it. The result is that the only animals that can live are those 

 which have sufficiently rapid powers of locomotion to follow the 

 rains, or are sufficiently strong to hold their own in the fight 

 for water round the pools, or to survive through long periods 

 without drinking. Unless animals are followed, one cannot 

 realise how far they wander, Harris and I kept on the track 

 of a herd of elephant on the Tana, and followed it all the way 

 from Merifano till close to the coast. Several times we found 

 tracks that could not have been made more than an hour 

 previously, and once we heard them trumpeting and playing 

 in a swamp beside our camp. But we never caught sight of 

 them. The distance we followed them, however — only thirty 

 miles — is little compared with that which hunters sometimes 

 have to chase a herd, M, Foa, for example, in his recent book,^ 

 tells us how he tracked a herd of elephant for seventeen days, 

 going as quickly as he could, before he finally came up with it. 

 Other animals, such as the buffalo, travel in the same way. 

 They walk slowly, feeding as they go, but often journeying 

 twenty or thirty miles as the crow flies (or is supposed to fly), 

 from one night's resting-place to the next. Only animals of 



^ Edouard Foa, Mes grandes C/iasses dans I'A/nqi/e Centrale (1894), p. 285. 



