PARENT SESSION
Poster Session #31: Animal Population and Community Ecology I.
Wednesday, August 7. Presentation from 5:00 PM to 6:30 PM. Exhibit Hall B & C, TCC

Contribution of immigration to population growth in Chrysemys picta picta (eastern painted turtle).

Bowne, David^*,1, ¹ University of Virginia, Charlottesville, VA

ABSTRACT- Recruitment is one of the key processes in population growth but differentiating immigration and birth, the components of recruitment, has proven difficult. This differentiation is needed, however, to determine the relative contribution of local versus regional factors to population growth. I addressed this issue by determining the factors controlling population growth of adult female Chrysemys picta picta (eastern painted turtle). A four-year mark-recapture study was conducted on and around Blandy Experimental Farm, Virginia. The contribution of survival and recruitment to population growth in three ponds was estimated using the Pradel model in the program MARK. The number of female turtles moving between each pond was used as an estimate of immigration. The number of subadult females maturing into adult females was used as an estimate of in situ reproduction. In Center Pond, adult survival was the most important component of population growth in 2000 and 2001. In contrast, recruitment played the key role (58%) in population growth in 1999, with 67% of the recruitment being attributed to immigration. Recruitment was of overwhelming importance to population growth in Rattlesnake Spring in each year and was comprised solely of immigration. Over 86% of the rapid growth between 1998 and 1999 in Jones Pond is attributed solely to immigration. In contrast, adult survival was more important in the following years. These results demonstrate the important role of immigration on population dynamics.

KEY WORDS: immigration, recruitment, population growth, painted turtle