Spatial disease ecology is emerging as a new field that requires the integration of complementary approaches to address how the distribution and movements of hosts and parasites may condition the dynamics of their interactions. In this context, migration, the seasonal movement of animals to different zones of their distribution, is assumed to play a key role in the broad scale circulation of parasites and pathogens. Nevertheless, migration is not the only type of host movement that can influence the spatial ecology, evolution, and epidemiology of infectious diseases. Dispersal, the movement of individuals between the location where they were born or bred to a location where they breed, has attracted attention as another important type of movement for the spatial dynamics of infectious diseases. Host dispersal has notably been identified as a key factor for the evolution of host-parasite interactions as it implies gene flow among local host populations and thus can alter patterns of coevolution with infectious agents across spatial scales. However, not all movements between host populations lead to dispersal per se. One type of host movement that has been neglected, but that may also play a role in parasite spread is prospecting, i.e., movements targeted at selecting and securing new habitat for future breeding. Prospecting movements, which have been studied in detail in certain social species, could result in the dispersal of infectious agents among different host populations without necessarily involving host dispersal. In this article, we outline how these various types of host movements might influence the circulation of infectious disease agents and discuss methodological approaches that could be used to assess their importance. We specifically focus on examples from work on colonial seabirds, ticks, and tick-borne infectious agents. These are convenient biological models because they are strongly spatially structured and involve relatively simple communities of interacting species. Overall, this review emphasizes that explicit consideration of the behavioral and population ecology of hosts and parasites is required to disentangle the relative roles of different types of movement for the spread of infectious diseases.
We thank David Gremillet, Jacob Gonzalez-Solis, Raul Ramos, Elena Gomez-Diaz, Christophe Barbraud, Henri Weimerskirch, Karine Delord, Cedric Marteau, Elisa Lobato Celine Toty, and Nicolas Giraud for help on different aspects of this work. We also thank Alexa McKay and Bethany Hoye for organizing the SICB symposium where we presented this review.
We acknowledge support from ANR (EVEMATA and ESPEVEC grants, respectively ANR-11-BSV7-003 and ANR-13-BSV7-0018), French Polar Institute (IPEV) programs n8333 (PARASITO-ARCTIQUE) and n81151 (ECOPATH), OSU OREME and ZATA. M.D. postdoctoral fellowship is funded by the National Research Foundation, South Africa (NRF - N00595). R.G. acknowledges support from an AXA Research Fund postdoctoral grant and V.B. from a LabEx CeMEB (Mediterranean Centre for Environment and Biodiversity) postdoctoral grant. The work involving animals in the field was approved by the Norwegian Animal Research Authority, the Comite de l’Environnement Polaire and the Reserve Nationale Naturelle des Terres Australes et Antarctiques Francaises.