8 THE ECOLOGY OF ANIMALS 



This complete knowledge has not yet been obtained 

 for any species. One reason is that comparatively 

 few ecological surveys of animal communities have 

 yet been completed. This phase of animal ecology 

 stands to-day at the point where plant ecology stood 

 in 1905, and where geology stood at the end of the 

 eighteenth century. It follows from this that we 

 still know comparatively little about the manner in 

 which animal communities are organized. Certain 

 principles are, however, beginning to emerge clearly, 

 and will be noted later. But in this phase of animal 

 ecology much work remains to be done, work which 

 has a number of attractions for the student, although 

 beset with considerable difficulties. The attractions 

 are that ecological surveys bring the student into 

 direct contact with Uve animals in a state of nature, 

 while at the same time almost always leading on to 

 special problems whose existence would not otherwise 

 have been suspected. And such surveys afford an 

 insight, that no other method gives, into the astound- 

 ing richness and complexity of animal life. They also 

 provide a sense of proportion which prevents undue 

 importance being given to one special group of animals. 



The difficulties of such surveys lie chiefly in the 

 actual labour involved in collecting and determining 

 the species of animals captured. Such difficulties are 

 partly those of organization, of getting co-operation 

 from experts, and of ensuring that enough field work 

 is accomplished to give a fair picture of the animal 

 community studied ; but there are also technical 

 obstacles connected with proper preservation of 

 specimens, etc., which can only be overcome by 

 experience. For these reasons beginners are strongly 

 advised to select as simple and limited an animal 

 community as possible, rather than to attempt single- 

 handed a survey of some very complex community 

 such as a wood or a lake. Ecological surveys in 

 high Arctic regions have proved the advantages of 

 studying animal communities containing compara- 



