Functional macronutritional generalism in a large omnivore, the brown bear.

摘要: We combine a recently developed framework for describing dietary generalism with compositional data analysis to examine patterns of omnivory in large widely distributed mammal. Using the brown bear (Ursus arctos) as model species, we collected and analyzed from literature estimate proportions macronutrients (protein, carbohydrate, lipid) diets populations. Across their range, bears consumed diversity foods that resulted annual population varied macronutrient proportions, suggesting wide fundamental niche. The variance matrix pairwise log-ratios indicated most variable among was while protein lipid were more proportional or codependent (i.e., relatively constant log-ratios). Populations anthropogenic foods, such agricultural crops supplementary feed (e.g., corn), had higher geometric mean proportion lower protein, diets. Seasonally, during autumn compared spring. subsidies, however, carbohydrate across seasons populations natural Proportions similar those selected experiments by captive bears, which optimized primarily fat mass gain, observed hyperphagic prehibernation However, majority these consuming typically protein. Some close summer. Our results suggest is functional adaptation enabling them occupy diverse range habitats tolerate variation nutritional composition availability food resources. Furthermore, show human-sourced have different relative