1. Transmission of parasites between host species affects host population dynamics,
interspecific competition, and ecosystem structure and function. In areas where wild
and domestic herbivores share grazing land, management of parasites in livestock
may affect or be affected by sympatric wildlife due to cross-species transmission.
2. We develop a novel method for simulating transmission potential based on both
biotic and abiotic factors in a semi-arid system in Botswana. Optimal timing of antiparasitic
treatment in livestock is then compared under a variety of alternative
host scenarios, including seasonally migrating wild hosts.
3. In this region, rainfall is the primary driver of seasonality of transmission, but wildlife migration
leads to spatial differences in the effectiveness of treatment in domestic animals.
Additionally, competent migratory wildlife hosts move parasites across the landscape.
4. Simulated transmission potential matches observed patterns of clinical disease in
livestock in the study area. Increased wildlife contact is correlated with a decrease
in disease, suggesting that non-competent wild hosts may attenuate transmission
by removing infective parasite larvae from livestock pasture.
5. Optimising the timing of treatment according to within-year rainfall patterns was
considerably more effective than treating at a standard time of year. By targeting
treatment in this way, efficient control can be achieved, mitigating parasite spillover
from wildlife where it does occur.
6. Synthesis and applications. This model of parasite transmission potential enables evidence-
based management of parasite spillover between wild and domestic species in a spatio-temporally dynamic system. It can be applied in other mixed-use systems to mitigate
parasite transmission under altered climate scenarios or changes in host ranges.