CONSERVATION CORRIDORS AND CONTAGIOUS-DISEASE - A CAUTIONARY NOTE

Recent conservation proposals frequently include the establishment of corridors to connect isolated patches of wildlife habitat. Much attent ion has been focused on the potential benefits of corridors with littl e note given to potentially adverse consequences. A simulation model i s developed here to study the effect of corridors on the survival of a metapopulation in the presence of a fatal disease that is spread by d irect contact between susceptible and infected individuals. For the di sease modeled here, a landscape of patches connected by corridors gene rally suffers fewer metapopulation extinctions than a landscape of iso lated patches. However, under a narrow range of conditions, results su ggest that corridors may dramatically increase the probability of meta population extinction This occurs when disease-induced mortality is lo w enough to allow infected individuals to spread the disease, but high enough to reduce population levels to the point that random demograph ic and environmental events cause frequent metapopulation extinctions. This has important implications for the design and management of cons ervation reserve networks. Although discussion focuses primarily on co nservation corridors, the model results apply to any management techni ques that increase the movement of individuals among populations.