lieve tliat in an intnuluctory Ixxik it is desirable 

 to approach the subject from a statistical point-of- 

 view. Too few readers will have an adequate sta- 

 tistical background, and the introduction to the 

 subject matter of ecology should not be delayed 

 until an adequate background of statistics is ob- 

 tained — as necessary as that is to advanced work 

 in the field. 



1 have not thought it desirable to devote a spe- 

 cial chapter to applied ecology or, more particu- 

 larlv, to wildlife management. The fundamental 

 principles of wildlife management are the same 

 as the fundamental principles of ecology, since 

 wildlife biology is the ecology of game species. 

 Throughout the book, however, I have tried to 

 show the relation of basic concepts to problems 

 in wildlife management. The special obligation of 

 the wildlife manager is to make practical use of 

 these principles for the promotion of wildlife pop- 

 ulations. 



This book is designed for a course given at the 

 junior-senior-graduate level, to students who have 

 at least a year's background in zoology. I give 

 such a course during the autumn semester. If I 

 were to give it during the spring, I would probably 

 change the order of study of the four sections to 

 I-IV-III-II. Section IV would here substitute 

 for Section II in providing the student with some 

 knowledge of communities before undertaking 

 section III. This would permit field studies late 

 in the spring to be more closely correlated with the 

 discussion of local habitats and communities. 



During the first semester at the University of 

 Illinois I have a half-day or a full-day trip every 

 Saturday until winter weather sets in, and there 

 are two half -day winter trips. Also included in 

 the field work is one weekend camping trip to 

 study communities not found locally. The stu- 

 dents get to see at first hand a large variety of 

 animals, and to measure population sizes by quan- 

 titative methods that may be crude but are never- 

 theless effective in stream riffles and pools, ponds 

 of different ages, bogs, lakes, grassland, deciduous 

 and coniferous forests, and serai stages as they 

 develop on rock, sand, pond, bog, floodplain. and 

 abandoned strip-mine areas. Some experimenta- 

 tion is also done in the field to analyze the manner 

 in which both aquatic and terrestrial species re- 



spdtul to eiiviroiuneiUal factors. There is a small 

 amount of laboratory work for learning quantita- 

 tive methods of counting plankton, examining dif- 

 ferent kinds of respiratory systems in a(|uatic 

 organisms, searching and identifying micro- 

 organi.sms in the soil, experiments in choice of 

 habitats, and map-making. Methods for measur- 

 ing i)roductivity are discussed but actual practice 

 with these methods is left for an advanced class. 



Knough material is given on plants in this 

 luiok. it is hoped, to bring out their essential place 

 in the ecosystem and to emphasize the bioecologi- 

 cal point-of-view. I believe it would be possible 

 for an instructor to use this textbook in a course 

 in general ecology by supplementing in lectures 

 tlie material and concepts jiresented in the book 

 with additional material on plants. 



Some care has been taken with taxonomic 

 nomenclature. Common names are used through- 

 out the text as far as possible, with the scientific 

 nomenclature restricted to the index. Authorities 

 followed for most scientific names are the follow- 

 ing. Mammals — North America : Miller and Kel- 

 logg 1955 ; Eurasia : I-^llerman and Morrison-Scott 

 1951. Birds— A.O.U. Checklist 1957. Reptiles 

 and amphibians — Schmidt 1953. Fish — Bailey 

 1960. Invertebrates — as given by authors, not 

 standardized. Trees — Dayton et al. 1953. Grasses 

 — Hitchcock 1951 ; and other plants, Fernald 

 1950, Rydberg 1954. Common names of mam- 

 mals are mostly from Hall 1957; birds, A.O.U. 

 Checklist 1957; reptiles and amphibians, Conant 

 1958; and fish, Bailey 1960. 



Pertinent references to literature are cited in 

 the text in connection with each major topic. 

 These references serve only as an introduction to 

 the very extensive literature in ecolog)-. 



Finally, I wish to acknowledge the help of 

 many persons in the preparation of this text, par- 

 ticularly, Stanley A. Cain, Edward S. Deevey, 

 Ralph W. Dexter, Paul L. Errington, F. E. J. 

 Fry, Clarence J. Goodnight, F. T. Ide, Bostwick 

 Ketchum, Ernst Mayr, Howard T. Odum, Or- 

 lando Park, F"rank Pitelka, W. 1--. Ricker, Gordon 

 .\. Riley, M. D. F. Udvardy, and R. H. Whitta- 

 ker. In addition, several of my colleagues at the 

 University of Illinois read and commented on 

 early drafts of chapters. John Riina, of Prentice- 



Preface 



