Abstract
Source-sink dynamics are an emergent property of complex species–landscape interactions. A better understanding of how human activities affect source-sink dynamics has the potential to inform and improve the management of species of conservation concern. Here we use a study of the northern spotted owl (Strix occidentalis caurina) to introduce new methods for quantifying source-sink dynamics that simultaneously describe the population-wide consequences of changes to landscape connectivity. Our spotted owl model is mechanistic, spatially-explicit, individual-based, and incorporates competition with barred owls (Strix varia). Our observations of spotted owl source-sink dynamics could not have been inferred solely from habitat quality, and were sensitive to landscape connectivity and the spatial sampling schemes employed by the model. We conclude that a clear understanding of source-sink dynamics can best be obtained from sampling simultaneously at multiple spatial scales. Our methodology is general, can be readily adapted to other systems, and will work with population models ranging from simple and low-parameter to complex and data-intensive.
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Acknowledgments
Our NSO simulation model could not have been developed without the invaluable assistance generously provided by Robert Anthony, Katie Dugger, Paul Henson, Brendon White, and Betsy Glenn. We are indebted to Robert Schooley, Barry Noon, and an anonymous reviewer for many detailed suggestions that greatly improved the manuscript. This work was supported in part by USFWS Agreements 134250BJ151 and F12AC01135 to JRD, and grants RC-1541 and RC-2120 to JL from the Strategic Environmental Research and Development Program. The information in this document has been funded in part by the U.S. Environmental Protection Agency. It has been subjected to review by the National Health and Environmental Effects Research Laboratory’s Western Ecology Division and approved for publication. Approval does not signify that the contents reflect the views of the Agency, nor does mention of trade names or commercial products constitute endorsement or recommendation for use.
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Schumaker, N.H., Brookes, A., Dunk, J.R. et al. Mapping sources, sinks, and connectivity using a simulation model of northern spotted owls. Landscape Ecol 29, 579–592 (2014). https://doi.org/10.1007/s10980-014-0004-4
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DOI: https://doi.org/10.1007/s10980-014-0004-4