Perturbation analysis for patch occupancy dynamics

Authors

  • Julien Martin,

    Corresponding author
    1. Florida Cooperative Fish and Wildlife Research Unit, University of Florida, Gainesville, Florida 32611-0485 USA
    2. Patuxent Wildlife Research Center, United States Geological Survey, 12100 Beech Forest Road, Laurel, Maryland 20708 USA
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  • James D. Nichols,

    1. Patuxent Wildlife Research Center, United States Geological Survey, 12100 Beech Forest Road, Laurel, Maryland 20708 USA
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  • Carol L. McIntyre,

    1. National Park Service, 4175 Geist Road, Fairbanks, Alaska 99709 USA
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  • Gonçalo Ferraz,

    1. Smithsonian Tropical Research Institute/Instituto Nacional de Pesquisas da Amazônia, Avenida André Araújo, Manaus, 69011 AM, Brazil
    2. Instituto Leônidas e Maria Deane, FIOCRUZ, Rua Teresina, Manaus, 69057 AM, Brazil
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  • James E. Hines

    1. Patuxent Wildlife Research Center, United States Geological Survey, 12100 Beech Forest Road, Laurel, Maryland 20708 USA
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Abstract

Perturbation analysis is a powerful tool to study population and community dynamics. This article describes expressions for sensitivity metrics reflecting changes in equilibrium occupancy resulting from small changes in the vital rates of patch occupancy dynamics (i.e., probabilities of local patch colonization and extinction). We illustrate our approach with a case study of occupancy dynamics of Golden Eagle (Aquila chrysaetos) nesting territories. Examination of the hypothesis of system equilibrium suggests that the system satisfies equilibrium conditions. Estimates of vital rates obtained using patch occupancy models are used to estimate equilibrium patch occupancy of eagles. We then compute estimates of sensitivity metrics and discuss their implications for eagle population ecology and management. Finally, we discuss the intuition underlying our sensitivity metrics and then provide examples of ecological questions that can be addressed using perturbation analyses. For instance, the sensitivity metrics lead to predictions about the relative importance of local colonization and local extinction probabilities in influencing equilibrium occupancy for rare and common species.

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