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Research Techniques in Animal Ecology - Chapter 4

Chapter 4 Delusions in Habitat Evaluation: Measuring Use, Selection, and Importance Management of wildlife populations, whether to support a harvest, conserve threatened species, or promote biodiversity, generally entails habitat management. Habitat management presupposes some understanding of species’ needs. | Chapter 4 Delusions in Habitat Evaluation Measuring Use Selection and Importance David L. Garshelis Management of wildlife populations whether to support a harvest conserve threatened species or promote biodiversity generally entails habitat management. Habitat management presupposes some understanding of species needs. To assess a species needs researchers commonly study habitat use and based on the results infer selection and preference. Presumably species should reproduce or survive better i.e. their fitness should be higher in habitats that they tend to prefer. Thus once habitats can be ordered by their relative preference they can be evaluated as to their relative importance in terms of fitness. Managers can then manipulate landscapes to contain more high-quality habitats and thus produce more of the targeted species. Habitat manipulations specifically intended to produce more animals have been conducted since at least the days of Kublai Khan a.d. 1259 1294 Leopold 1933 . However the processes of habitat evaluation are fraught with problems. Some problems are specific to the methods used in the data collection or analyses. Many of these problems have already been recognized and discussions about them in the literature have prompted a host of evolving techniques. Other problems are inherent in the two most basic assumptions of this approach that researchers can discern habitat selection or preference from observations of habitat use and that such selection perceived or real relates to fitness and hence to population growth rate. My goal is to illuminate the scope of the problems involved in habitat evaluation. Assessments of habitat selection and presumed importance are done so often and study methods have become so routine that it is apparent that researchers and managers tend to believe that the major problems have for the most part been overcome. I contend that this view is overly sanguine and propose a reconsideration of the ways in which habitat .