This research involves a field experiment that will determine the impact of helminth parasitism on a cyclic snowshoe hare population during its first 2 years of decline from peak abundance. The overwinter food shortage and intense predation that typically occur at this stage of the hare cycle, together with major demographic changes, provide a unique opportunity to test hypotheses about parasitism's interaction with malnutrition and predation. The field experiment entails a 2 x 2 factoral design with three replicates. Each replicate consists of food-added and food-normal treatments within which the demographic attributes (survival, reproduction, movements, etc.) of parasite-free and parasite-normal cohorts will be monitored through radio telemetry. Pilot studies have demonstrated our ability to purge gastrointestinal helminths and lungworms from snowshoe hares in the wild and to assess proximate cause of death of radio-collard hares. The project will test long-standing theory or factors controlling population aples in vertebrate species.
