USING BLACK BEARS TO TEST IDEAL-FREE DISTRIBUTION MODELS EXPERIMENTALLY

摘要: Models on the distribution of animals are invaluable in understanding how individuals and, ultimately, populations respond to ecological processes. Rarely, have they been applied conservation issues at a landscape level. We capitalized previously unavailable novel food resource, found juxtaposition urban and wildland areas, test generality ideal-free (IFD) models using mammalian carnivore, black bear (Ursus americanus). The primary question we addressed was whether an increase prevalence geographical region reflects population or level redistribution. Combining spatial temporal data sets with empirically obtained information spanning 12‐15 years, contrasted demographic, lifehistory, reproductive parameters between urban‐wildland interface (experimental) (control) areas Sierra Nevada Range Great Basin Desert western North America. Bears were expected natural versus artificially clumped resources according IFD model. Evidence only partially supported this idea because had densities 3 times historical values from same area, sex ratios 4.25 more skewed toward males, bears 30% larger body mass, home ranges reduced by 90% for males 70% females, entered dens significantly later than conspecifics. However, females urban-interface gave birth number cubs, although half as many dispersed successfully relative females. Further, higher proportion (0.57) potential which young, compared (0.29). present evidence suggesting that Lake Tahoe basin conform primarily ideal-despotic Our findings reallocation, rather demographic increase, reemphasize knowledge about correlates individual performance over time helps understand extent humans change ecosystems, their actions intentional not.