Daniel M. Tompkins, Alison M. Dunn, Matthew J. Smith, and Sandra Telfer
1. We review our ecological understanding of wildlife infectious diseases from the individual host to the ecosystem scale, highlighting where conceptual thinking lacks verification, discussing difficulties and challenges, and offering potential future research directions.
2. New molecular approaches hold potential to increase our understanding of parasite interactions within hosts. Also, advances in our knowledge of immune systems makes immunological parameters viable measures of parasite exposure, and useful tools for improving our understanding of causal mechanisms.
3. Studies of transmission dynamics have revealed the importance of heterogeneity in host behaviour and physiology, and of contact processes operating at different spatial and temporal scales. An important future challenge is to determine the key transmission mechanisms maintaining the persistence of different types of diseases in the wild.
4. Regulation of host populations is too complex to consider parasite effects in isolation from other factors. One solution is to seek a unified understanding of the conditions under which (and the ecological rules determining when) population scale impacts of parasites can occur.
5. Good evidence now shows that both direct effects of parasites, and trait mediated indirect effects, frequently mediate the success of invasive species and their impacts on recipient communities. A wider exploration of these effects is now needed.
6. At the ecosystem scale, research is needed to characterise the circumstances and conditions under which both fluxes in parasite biomass, and trait mediated effects, are significant in ecosystem processes, and to demonstrate that parasites do indeed increase ‘ecosystem health’.
7. There is a general need for more empirical testing of predictions and subsequent development of theory in the classic research cycle. Experimental field studies, meta-analyses, the collection and analysis of long-term datasets, and data constrained modelling, will all be key to advancing our understanding.
8. Finally, we are only now beginning to understand the importance of cross-scale interactions associated with parasitism. Such interactions may offer key insights into bigger picture questions such as when and how different regulatory factors are important, when disease can cause species extinctions, and what characteristics are indicative of functionally resilient ecosystems.
In Journal of Animal Ecology
All copyrights reserved by Wiley 2007.
M. Begon, S. Telfer, S. Burthe, X. Lambin, M. Smith, and S. Paterson. Effects of abundance on infection in natural populations: field voles and cowpox virus., Epidemics, 6 October 2008.
Matthew J. Smith, Sandra Telfer, Eva R. Kallio, Sarah Burthe, Alex R. Cook, Xavier Lambin, and Michael Begon. Host-pathogen time series data in wildlife support a transmission function between density and frequency dependence, Proceedings of the National Academy of Sciences of the United States of America, 106(19), pp. 7905-7909, 12 May 2009.
Begon, M., Telfer, S., Smith, M.J., Burthe, S., Paterson, S., Lambin, and X.. Seasonal host dynamics drive the timing of recurrent epidemics in a wildlife, Proceedings of the Royal Society B: Biological Sciences, 20 January 2009.