Landscape use by wide-ranging mammals of the Brazilian Cerrado.

摘要

Conserving animals beyond parks is critical since even the largest reserves may be too small to maintain viable populations for many wide-ranging species. Identification of sites that will promote population persistence is a high priority, in particular, for protected areas that reside in regions of otherwise extensive habitat loss. This is the case for Emas National Park, a small but important protected area located in the Brazilian Cerrado. In order to determine the relative importance of resources found within the Park, as well as to identify key sites outside the reserve, I used scat detection dogs to survey for five large mammals of conservation concern: maned wolf (Chrysocyon brachyurus), puma (Puma concolor ), jaguar (Panthera onca), giant anteater ( Myrmecophaga tridactyla), and giant armadillo (Priodontes maximus). I quantified the effectiveness of dog teams to determine species presence and evaluated how each of the species were distributed within and around Emas National Park. I assessed how measurable sample quality factors influence DNA amplification success as well as Measurable hormone quantities and found that amount of odor and moisture (indicating freshness) predicted mtDNA amplification success, as well as mean hormone levels. To determine how each of the species were using resources, I fit resource selection probability models, which show how each species uses sites relative to those available. Finally, to evaluate how ranging behavior may influence physiological health in maned wolves, which are nearly endemic to the Cerrado, I measured fecal glucocorticoids, indicative of stress, thyroid hormone, indicative of nutritional status, and androgens, indicative of reproductive health. Glucocorticoid concentrations increased with distance from natural habitat patches and during times of peak harvest activity. Thyroid hormone levels were higher, indicating good nutritional status, in areas with more cropland, thus supporting my hypothesis that maned wolves select agricultural areas due to availability of rodents. Progestin levels in females were higher inside than outside the Park, suggesting that females have higher reproductive success in the Park compared to those residing outside the Park. These analyses illustrate the landscape features that must be maintained if we are to promote persistence of diverse, wide-ranging species.