i68 ANIMAL ECOLOGY 



it was. It frequently happens that the person who chances 

 to notice some fact of vital interest to the ecologist working 

 on some problem is not the ecologist himself, but some other 

 kind of biologist, or perhaps some one who is not a scientist at 

 all. If the observations made by such people could be backed 

 up by specimens of the animals, it would be possible to collect 

 a vast amount of very valuable data. 



8. It is worth while bearing in mind that the ecologist can 

 frequently get, in this way, facts which he would otherwise 

 never come across at all by himself, and he should make every 

 effort to enlist the help of other people to co-operate. In this 

 connection it is worth while quoting from the rules which were 

 made out by Dr. Levick for the use of non-biological members 

 of the Northern Party of Scott's Antarctic Expedition.121 

 They ran as follows : " Members are invited to write in this 

 book notes on anything of interest seen by them relating to 

 birds, seals, whales, etc., appending their initials and bearing 

 in mind the following observations : 



" (i) Never write down anything as a fact unless you are 

 absolutely certain. If you are not quite sure, say ' I think I 

 saw ' instead of ' I saw,' or * I think it was ' instead of ' It 



was ' ; but make it clear whether you are a little doubtful or 



very doubtful. 



" (2) In observing animals disturb them as little as 



possible. . . . 



" (3) Notes on the most trivial incidents are often of great 



value, but only when written with scrupulous regard to 



accuracy." 



These rules are useful for zoologists also. 



9. Having given these general suggestions about ecological 



work, we will now consider the best methods of carrying out 



a general primary ecological survey of animal communities. 



Many valuable hints are contained in Tansley's book,^^ since 



to a large extent the methods of primary survey are essentially 



the same for plants and animals. The process of making such 



a survey is as follows : 



First of all, have a general look round the area to be studied, 



and get an idea of the main habitats that exist, and in 



