Dynamic Habitat and Population Analysis: an Approach to Resolve the Biodiversity Manager’s Dilemma

Biodiversity managers face a dilemma of choosing between ‘‘coarse-filter’’ approaches that deal with the habitats of several species and ‘‘fine-filter’’ approaches that address population viability of one or a few species. We present an approach for local spatial scales that integrates habitat-based and population-based methods to focus research and management on the species in a community that are most at risk of extinction and on the places in the landscape most important to these species. The steps in Dynamic Habitat and Population (DHP) Analysis are: 1) determine which species in the planning area most merit field study based on existing data; 2) use local field data to select species that most merit demographic study; 3) use demographic data to model population viability of the species deemed most at risk; 4) design and evaluate alternative management strategies for key species and landscape settings. We review each step and provide an example for land birds in a portion of the Greater Yellowstone Ecosystem. Among the 143 species of land birds likely in the study area, we selected 13 species most at risk of extinction. These were mostly neotropical migrant passerines that specialized on low-elevation deciduous habitats that may serve as population source areas. We present a management plan for the multiple ownerships of the study area that seeks to maintain/restore population source habitats for key species. DHP Analysis provides a framework for biodiversity management for those regions identified as high priority for conservation by continental-scale assessment programs such as Gap Analysis. Our approach is designed to minimize local extinctions, which should reduce the risk of range-wide extinctions.