IGN 17

Ecology and Management of Source-Sink Dynamics

Thirty years ago, the introduction of source-sink theory changed the way ecologists think about species distributions: Specifically, source-sink theory means that species occur in unsuitable habitat types (sinks) due to movement from suitable habitat patches (sources). In principle, inferences about the ecology and management of populations should be informed by an understanding of the extent to which interacting populations function as sources or sinks. Nonetheless, ecologists still routinely infer habitat suitability from species occurrence and/or abundance, without considering the landscape context. In part, this discrepancy reflects the difficulty of measuring the joint effects of movement and demography in practice. This session will address novel and integrated applications of ecological theory, modeling, and empirical research to inform our understanding of source-sink dynamics at local, intermediate, and regional extents. We will showcase empirical studies investigating the source-sink status of populations of three major taxonomic groups – birds, amphibians, and butterflies – in major ecosystems throughout the United States, and discuss the implications of source-sink dynamics for management of these species. These case studies reveal a number of contrasting ways in which the general theory has been interpreted, and complementary ways in which different studies have related models to data for populations of species of management concern.