This subject is an introduction to the key ideas in the ecology of plants and animals. In presenting these ideas, the subject emphasises not only the ways in which they can be used to explain the distribution and abundance of species, but also their importance in helping understand the causes of extinction and providing the scientific basis for management of species. Topics include fertility and mortality; population dynamics and population regulation; life history strategies; interactions between species (competition, facilitation, predation, herbivory, parasitism); dynamics of communities; island biogeography; limits to the co-existence of species.