@article{mitchell_powell_2008, title={Estimated home ranges can misrepresent habitat relationships on patchy landscapes}, volume={216}, ISSN={["1872-7026"]}, DOI={10.1016/j.ecolmodel.2008.05.001}, abstractNote={Home ranges of animals are generally structured by the selective use of resource-bearing patches that comprise habitat. Based on this concept, home ranges of animals estimated from location data are commonly used to infer habitat relationships. Because home ranges estimated from animal locations are largely continuous in space, the resource-bearing patches selected by an animal from a fragmented distribution of patches would be difficult to discern; unselected patches included in the home range estimate would bias an understanding of important habitat relationships. To evaluate potential for this bias, we generated simulated home ranges based on optimal selection of resource-bearing patches across a series of simulated resource distributions that varied in the spatial continuity of resources. For simulated home ranges where selected patches were spatially disjunct, we included interstitial, unselected cells most likely to be traveled by an animal moving among selected patches. We compared characteristics of the simulated home ranges with and without interstitial patches to evaluate how insights derived from field estimates can differ from actual characteristics of home ranges, depending on patchiness of landscapes. Our results showed that contiguous home range estimates could lead to misleading insights on the quality, size, resource content, and efficiency of home ranges, proportional to the spatial discontinuity of resource-bearing patches. We conclude the potential bias of including unselected, largely irrelevant patches in the field estimates of home ranges of animals can be high, particularly for home range estimators that assume uniform use of space within home range boundaries. Thus, inferences about the habitat relationships that ultimately define an animal's home range can be misleading where animals occupy landscapes with patchily distributed resources.}, number={3-4}, journal={ECOLOGICAL MODELLING}, author={Mitchell, Michael S. and Powell, Roger A.}, year={2008}, month={Sep}, pages={409–414} }
 @article{powell_mitchell_1998, title={Topographical constraints and home range quality}, volume={21}, ISSN={["1600-0587"]}, DOI={10.1111/j.1600-0587.1998.tb00398.x}, abstractNote={The topography of an area affects the animals that live in at. Using digitized topographic maps of our mountainous study area in North Carolina. USA, and using radio telemetry data for locations of black bears Ursus americanus, we tested the hypotheses that topography influences home ranges of black bears and that topography affects access to resources by black bears. Use of space by bears correlated positively with steepness of slope but negatively with relative elevation. The perimeters of bears” home ranges aligned with ridges and valleys more than expected by chance and home ranges were oriented on major topographic features, such as watersheds and basins. Bears’ homo ranges had lower resource values than was optimal for their home range locations and access to resources was limited by topography'. Ignoring topography may lead researchers to misunderstand the ecology and behavior of animals that live in mountainous areas.}, number={4}, journal={ECOGRAPHY}, author={Powell, RA and Mitchell, MS}, year={1998}, month={Aug}, pages={337–341} }