1 - Introduction to wildlife population growth rates

Summary

This book takes a fresh approach to some of the classic questions in ecology. In particular, what determines where a species lives and what determines its abundance? Despite great progress in the twentieth century much more remains to be done before we can provide full answers to these questions so that reliable predictions can be made as to what will be found in unstudied areas or times. We believe that the methods described and deployed in this book point the way forward. The core message of the book is that key insights come from understanding what determines population growth rate (pgr). We believe that application of this approach will make ecology a more predictive science.

In this chapter we begin with an introduction to the major themes of the book, and then after briefly indicating how population growth rate is defined, we describe the contents of the book in more detail. Those who require more background material will find a brief guide to available texts at the end.

Major themes

In briefest outline, the approach taken in this book is as follows. Questions as to what determines where species live are questions about what values of environmental factors allow populations to persist. Populations persist where pgr ≥ o, so the environmental conditions that produce pgr ≥ o are the conditions in which the species can live. This line of reasoning suggests that to understand what determines where species live, we should study the relationships between environmental factors and pgr.