The Use of Conceptual Models in Population Ecology

The concept of environment that was put forward by Andrewartha and Birch (1954) may be summarized as follows. (a) The concept relates to the environment of an individual. (b) The characteristic feature of environment is that it influences an animal's chance to survive and multiply. Anything at all (not being part of the animal itself) that influences the animal's chance to survive and multiply is, by definition, part of its environment. (c) The environment of any animal may be analysed into four major components, food, other animals (including organisms causing disease), weather and the place in which the animal lives.