OOS 60-1
Interactions between parasites and the structure of food webs

Thursday, August 13, 2015: 8:00 AM
315, Baltimore Convention Center
Andy P. Dobson, Ecology and Evolutionary Biology, Princeton University, Princeton, NJ
1) Background/Question/Methods

Biodiversity is defined by the huge number of species that inhabit the planet.  Our best estimates suggest that half of these species are parasitic on the other half, but it could be that as many as ninety percent of species are parasitic.  Significant concerns arise when parasites become pathogens; and most of the study of parasites focuses on these problems and their prevention.  Here I’ll present an alternative view and focus on how parasite species interact with each other and the consequences of this for key questions such as persistence, as well as how this influences the health of their host populations.   I will compare the results of these analysis with analyses that examine how host diversity impacts the dynamics of shared pathogens. 

This talk will use a mixture of long-term field studies and mathematical models to to examine the interactions between host and pathogen diversity in the Serengeti ecosystem in Tanzania, East Africa.  I’ll principally focus on viral pathogens shared between carnivores and domestic dogs (canine distemper virus and canine parvovirus) and those shared between ungulates, cattle and goats (rinderpest and Peste des Petite Ruminantes virus).  For the bigger picture, I’ll also draw on examples from work on parasite diversity and abundance in Yellowstone and the salt-marshes of coastal California.

2) Results/Conclusions

The analyses suggests that pathogens may play a previously unsuspected role in enhacing each others persistence, while also confounding attempts that focus to control on a single pathogen in the system.  Curious counterexamples occur when pathogens shared between hosts enhance the success of control of some pathogens and reduce the efficacy of control in others.