Résumé
Parasites are thought to have a key role in determining the structure of animal communities. Most of the evidence for this is based on how different host species vary in their susceptibility to infection or its consequences. This chapter reviews the current theoretical and empirical knowledge on this topic. It then argues and illustrates the role that parasites can have in engineering ecological processes via their effects on a host’s phenotype and on the resources — biotic or abiotic — available to hosts and their competitors. These ideas are discussed in relation to possible management strategies for conservation.