BEE: SG: How host migratory behavior shapes the evolution of parasite virulence

University Of Minnesota-Twin Cities, Minneapolis MN

Investigators

Abstract

From birds to whales, monarchs to fish, animals across the globe embark on seasonal migrations each year, traveling thousands of miles. These big movement patterns also affect smaller organisms – namely the parasites that infect animal hosts. Over the course of a year, migrants come into contact with different non-migratory animals. Since migratory and non-migratory species may each be infected by different parasites, these new contacts present opportunity for parasite transmission between species. However, it is not clear under what conditions parasites are actually able to move between hosts, and how costly parasites will be to their new hosts. The aim of this project is to develop a predictive understanding of when parasites are able to move between migratory and non-migratory hosts, and how much parasites are likely to decrease the survival of their new hosts. Researchers at the University of Minnesota (including undergraduate and graduate students) will accomplish this by developing novel mathematical models. The outcome of this work will help shape our understanding of parasite transmission between migratory wildlife and sedentary livestock and aquaculture species. The findings will be communicated to the scientific community through national and international presentations and publications, and to the public through local outreach programs at a natural history museum and farmer’s markets. Despite increasing concern as to how migratory species influence emerging infectious disease, there is no conceptual framework to predict under what conditions parasites can move between hosts and what the consequences will be for parasite virulence (parasite-induced host mortality). Parasites are under selection for strategies that increase transmission to new hosts. Intriguingly, predictions from general theory (interpreted in the context of migration) suggest that parasites should be more virulent in migratory hosts, while empirical patterns from parasites of migratory hosts suggest the opposite. This research will develop theory specifically aimed at understanding how host migration patterns should shape parasite virulence, in order to reconcile this conflict in the literature. The models will test the role of (i) host life history parameters, (ii) the degree to which parasites impose similar costs in different host sub-populations, and (iii) cost currency of parasite infection, in shaping parasite transmission-virulence strategy. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.