Spatial compartmentalization: A nonlethal predator mechanism to reduce parasite transmission between prey species.

Abstract

Predators can modulate disease transmission within prey populations by influencing prey demography and behavior. Predator-prey dynamics can involve multiple species in heterogeneous landscapes; however, studies of predation on disease transmission rarely consider the role of landscapes or the transmission among diverse prey species (i.e., spillover). We used high-resolution habitat and movement data to model spillover risk of the brainworm parasite (<i>Parelaphostrongylus tenuis</i>) between two prey species [white-tailed deer (<i>Odocoileus virginianus</i>) and moose (<i>Alces alces</i>)], accounting for predator [gray wolf (<i>Canis lupus</i>)] presence and landscape configuration. Results revealed that spring migratory movements of cervid hosts increased parasite spillover risk from deer to moose, an effect tempered by changes in elevation, land cover, and wolf presence. Wolves induced host-species segregation, a nonlethal mechanism that modulated disease emergence by reducing spatiotemporal overlap between infected and susceptible prey, showing that wildlife disease dynamics may change with landscape disturbance and the loss of large carnivores.