Carnivore Niche Partitioning in a Human Landscape.

AbstractTo minimize competitive overlap, carnivores modify one of their critical niche axes: space, time, or resources. However, we currently lack rules for how carnivore communities operate in human-dominated landscapes. We simultaneously quantified overlap in the critical niche axes of a simple carnivore community-an apex carnivore (), a dominant mesocarnivore (), and a subordinate small carnivore ()-in a human landscape featuring pastoralists and semidomestic carnivores (i.

Compound-specific δH analysis highlights the relationship between direct assimilation and de novo synthesis of amino acids from food and water in a terrestrial mammalian omnivore.

Hydrogen isotope (δH) analysis has been routinely used as an ecological tracer for animal movement and migration, yet a biochemical understanding of how animals incorporate this element in the synthesis of tissues is poorly resolved. Here, we apply a new analytical tool, amino acid (AA) δH analysis, in a controlled setting to trace the influence of drinking water and dietary macromolecules on the hydrogen in muscle tissue. We varied the δH of drinking water and the proportions of dietary protein and carbohydrates with distinct hydrogen and carbon isotope compositions fed to house mice among nine treatments.

Assimilation and discrimination of hydrogen isotopes in a terrestrial mammal.

Stable isotope analysis has revolutionized the way ecologists study animal resource use from the individual to the community level. Recent interest has emerged in using hydrogen isotopes (H/H) as ecological tracers, because they integrate information from both abiotic and biotic processes. A better physiological understanding of how animals assimilate hydrogen and use it to synthesize tissues is needed to further refine this tool and broaden its use in animal ecology.