Preface 



The science of ecology, born at the beginning 

 of the present century after a gestation period 

 of several hundreds of years, has now matured 

 into an honored and respected scholarly disci- 

 pline and field of research. This book is an efifort 

 to summarize the basic concepts and principles of 

 the subject and present the elementary factual in- 

 formation with which a person to be competent in 

 this field should be familiar, especially as these 

 things apply to animals. 



After a Background section for orientation, 

 local communities and habitats are discussed in 

 some detail. It is my firm belief that one begin- 

 ning the study of ecology should first of all be- 

 come thoroughly acquainted with the places where 

 animals may be found in nature, what kinds of 

 organisms occur in different habitats, the abun- 

 dance and interrelations of organisms in these 

 habitats, the behavior and the life requirements of 

 the principal species, and the structure and succes- 

 sion of communities. The reader well founded in 

 this knowledge is ready to understand the ecologi- 

 cal processes and community dynamics which are 

 presented in the third section. In the fourth and 

 final section, the reader is introduced to the broad 

 field of geographic ecology, which, will give him 

 some knowledge of how animals are distributed 

 over the world, and why they occur where they do. 



Physiological ecology, the study of the manner 

 in which organisms respond and adjust to envi- 

 ronmental factors, is dealt with sparingly. The 

 proper development of this subject takes one ex- 

 tensively into laboratory experimentation, which 

 is best left to the advanced student. Our emphasis 

 is kept on the study of the free-living organism in 

 its natural environment. Although the quantita- 

 tive aspect of ecology is emphasized, I do not be- 



