NCEAS Project 7040

Using biological invasions to test predictions of population control by parasites

  • Mark E. Torchin

ActivityDatesFurther Information
Postdoctoral Fellow1st October 2003—31st August 2004Participant List  

Introduced species are a major threat to global biodiversity, ranked second only to habitat loss (Vitousek 1990, Wilcove et al. 1998). The damage caused by exotic species results from the high population densities and large body sizes that they attain in their new location (Vitousek 1990, Wilcove et al. 1998, Ruiz et al. 1999, Torchin et al. 2001, 2002). Escape from the effects of natural enemies is a frequent explanation given for the success of introduced species (Keane and Crawley 2002, Shea and Chesson 2002). Recently, Torchin et al. (in press) demonstrated that introduced species are parasitized by half the number of parasite species compared to where they are native and that introduced populations are also less heavily parasitized (% infected) than native populations. However, while parasites are ubiquitous and pervasive, the extent to which parasites mediate invasions and result in increased ecological performance of introduced species has not been evaluated. Further, the extent to which introduced parasites and pathogens are responsible for damage to native species has not been quantified. Using existing data, I propose to extend a database which I developed for a NCEAS working group (Diseases and Conservation Biology) and employ a meta-analysis to test several hypotheses which explore the role of parasites in biological invasions. Further, by using biological invasions as �natural experiments�, I will design this project to investigate a more fundamental question in ecology: How do parasites affect the distribution and abundance of their hosts?

TypeProducts of NCEAS Research
Presentations Torchin, Mark E. 2004. Introduced species and their missing parasites: What's gained by their loss. Disease Ecology Symposium 2004. Ecological Society of America. Portland, Oregon.
Presentations Torchin, Mark E. 2004. Introduced species and their missing parasites: What's gained by their loss. American Association of Limnology and Oceanography 2004. American Association of Limnology and Oceanography. Honolulu, Hawaii.
Journal Article Torchin, Mark E.; Mitchell, Charles E. 2004. Parasites, pathogens, and invasions by plants and animals. Frontiers in Ecology and the Environment. Vol: 2. Pages 183-190.
Book Chapter Torchin, Mark E.; Kuris, Armand. 2005. Introduced marine parasites. Edited by Rhode, K. Marine Parasitology. CSIRO Publishing.