Detecting disease and parasite threats to endangered species and ecosystems.

Ecologists have recently begun to acknowledge the importance of disease and parasites in the dynamics of populations. Diseases and parasites have probably been responsible for a number of extinctions on islands and on large land masses, but the problem has only been identified in retrospect. In contrast, endemic pathogens and parasites may operate as keystone species, playing a crucial role in maintaining the diversity of ecological communities and ecosystems. Will recent advances in the understanding of parasite population biology allow us to predict threats to endangered species and communities?