Populations are often spatially structured. Understanding the effects of spatial structures such as sources and sinks, metapopulations, patchy networks, and isolated populations on population dynamics is critical for successful management.

The objective of this project is to develop an understanding of the relative importance of the factors that influence source-sink dynamics in general and to explore the implications of source-sink dynamics for the management of an endangered species, the black-capped vireo (Vireo atricapilla).

This project will use a combination of simulation modeling and field studies to explore source-sink dynamics in theoretical and real populations. Researchers will use a spatially explicit, individual-based, population model to identify the attributes of species and landscapes that tend to produce stronger source-sink dynamics. Field monitoring and demographic analyses then will be undertaken to identify sources and sinks for black-capped vireos on and around Fort Hood, Texas. A spatially explicit, individual-based population model will be used to identify the relative contributions of the various sources and sinks to overall population dynamics of black-capped vireos across their range and to explore the effects of habitat restoration, cowbird control, and climate change on their source-sink dynamics.

This project will benefit Department of Defense natural resource managers in three basic ways. First, the project will improve understanding of the factors that influence source-sink dynamics and thus help managers predict, monitor, and manage for them. Second, black-capped vireo managers at Fort Hood will gain a better understanding of the influence of habitat structure and landscape pattern on source-sink dynamics on base and perhaps more importantly, the role of surrounding off-base habitat in overall population dynamics. Finally, the project will provide black-capped vireo managers on and off Fort Hood with a tool (in the form of a parameterized model) for assessing the potential effects of different management and climate change scenarios on the vireo across its range. (Anticipated Project Completion - 2016)