Population Dynamics in Variable Environments

University Of Virginia Main Campus, Charlottesville VA

Investigators

Abstract

Three mechanisms that promote the persistence of populations in uncertain environments are: 1) a variable age at maturation, 2) repeated reproduction, and 3) dispersal between populations. The project will study 18 amphibian species that breed in a complex of 32 natural sinkhole ponds. All individuals of 7 species are photographed whenever they are captured. Computer-assisted matching of these images yields data for capture-recapture models to estimate population sizes and vital rates. These estimates will allow direct evaluation of population dynamics and persistence in uncertain environments under realistic assumptions. The detailed model for the most common focal species, Ambystoma opacum, will guide construction of an individual-based model for Ambystoma tigrinum, a species listed as endangered in several states. Population dynamics in spatially and temporally varying environments comprise an important area of population biology because they determine the context of life history adaptation and population differentiation. This study is also important because population ecology is the foundation for community ecology and for the development of plans for managing populations for harvest, pest control, or conservation action. The request for imaging equipment is supported within this award as part of NSF's Facilitation Awards for Scientists and Engineers with Disabilities, a funding mechanism that enables scientists with disabilities to more fully engage in the research process. The project will support doctoral and post-doctoral research. Undergraduates will be employed as field assistants during the summer.