PARENT SESSION

Community Ecology 4 -- Session Chair: Marianna Wood-- Van Duzer Theater

RESPONSES OF HANTAVIRUS HOST COMMUNITIES IN PANAMA TO SPECIES REMOVAL. Gerardo Suzan¹, Erika Marce¹, Robert Parmenter¹, Tomasz Giermakowsky¹, Blas Armien², Anibal Armien², Juan M. Pascale² and Terry Yates¹. ¹ Museum of Sothwestern Biology. Dept. of Biol. Univ. of New Mexico., Albuquerque, NM, USA; ² Instituto Conmemorativo GORGAS. Ave. Justo Arosemena y Calle 35. PO Box 6991, Panama, Panama, Panama.

ABSTRACT- Habitat fragmentation due to increased conversion of land to agricultural uses influenced the pattern of distribution of hantavirus host communities in Panama. We suggest, however, that other community attributes have as great or greater influence. Competent reservoir populations (CR) such as Oligoryzomys fulvescens (reservoir for Choclo virus) and Zygodontomys brevicauda (reservoir for Calabazo virus) could be influenced by species richness, evenness, diversity, and interspecific interactions within their community, particularly where fragmented landscapes are dominant. We hypothesized that 1) CR populations will increase when they are alone in the system, regardless of habitat type, 2) the highest infection rates will occur when CR dominate the system. To test these predictions, we removed alternative host species and non-host communities in 16 experimental plots and established 8 control plots with similar environmental conditions. All 24 plots were edges of small forest fragments in Azuero Peninsula. Each site was sampled monthly for three consecutive nights in five periods during the wet season (June-November 2003). A total of 1460 captures (905 individuals and 555 recaptures) involving 8 rodent species in 17640 trap-nights were performed. Despite being generalist species, the response of CR species populations to alternative host species removal differed strongly between sites. Even though the study was short-term, the size of CR populations was positively affected by the removal of the alternative host and non-hantavirus host species. Regardless of other variables that drive population dynamics in rodents, species diversity itself seems to play an important role in dynamics of CR populations. Long-term studies are needed to provide more detailed information about interaction between disease transmission, biodiversity loss, and habitat fragmentation. This potential approach will help to understand better the dynamics of natural populations and will have large implications for applied issues such as control and management of zoonotic diseases, epizootics, conservation, and wildlife management.

KEY WORDS: species removal, Hantavirus, Panama