io6 ANIMAL ECOLOGY 



fifty years they had nearly all disappeared, while a similar 

 fate is now threatening those of the southern hemisphere. In 

 the photograph in Plate VIII can be seen the skulls and bones 

 of a huge colony of walruses on Moffen Island, up in latitude 

 80° N., which were slaughtered as they lay there, by these 

 same early explorers. On the Galapagos Islands there is a 

 similar cemetery of giant tortoises, of which only the shells are 

 left to mark their former abundance. ^'^^^ Almost everywhere 

 the same tale is told — former vast numbers, now no longer 

 existing owing to the greed of individual pirates or to the 

 more excusable clash with the advance of agricultural 

 settlement. 



8. It is not much use mourning the loss of these animals, 

 since it was inevitable that many of them would not survive 

 the close settlement of their countries. The American bison 

 could not perform its customary and necessary migrations 

 when railways were built across the continent and when the 

 land was turned into a grain-producing area.^^ Our object 

 is rather to point out that the present numbers of the larger 

 wild animals are mostly much smaller than they used to be, 

 and that the conditions under which the present fauna has 

 evolved are in that respect rather different from what one might 

 imagine from seeing the world in its present state. At the 

 same time there is in many cases no reason why animals should 

 be reduced in numbers or destroyed to the extent that they 

 have been and still are. From the purely commercial point 

 of view it often means that the capital of animal numbers is 

 destroyed to make the fortune of a few men, and that all possible 

 benefits for any one coming later are lost. Enlightened govern- 

 ments are now becoming alive to this fact, and measures are 

 being taken to protect important or valuable animals. Thus 

 the fur seal on the Alaskan Islands, which was in some danger 

 of being gradually exterminated, has increased greatly under 

 protection. Since 1910 killing has been prohibited on the 

 Pribiloff Islands, except by Federal agents, and the herd of 

 seals had increased from 215,000 in 1910 to 524,000 in 1919.21 

 Again, the Siberian reindeer has been introduced into Alaska, 

 with similar favourable results in repopulating the country 



