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Wild rabbit (Oryctolagus cuniculus) populations have suffered a dramatic reduction over the last 30 years in Spain. Rabbit decline has been recurrently associated with several epizootics and habitat changes. The role of interspecific competition has been usually neglected. This study analyzes the effects of habitat suitability and wild boar (Sus scrofa) occurrence, a hypothetical predator and competitor species, on a small and isolated population of rabbits. To test this effect we used a GLM with the abundance of rabbits as response variable and wild boar occurrence as predictor. To avoid habitat confounding effects we included vegetation structure variables and elevation summarized in PCA factors. Rabbits showed a very restricted and aggregated distribution and a very low abundance across the study area. In contrast, wild boar was present in all sampled plots but one and showed moderatehigh abundance. The three best models included both wild boar occurrence and principal component factor 2. Rabbits were located in opened Mediterranean areas where trees were small and scarce, rock cover was low and wild boar occurrence was also low. Nowadays wild boar populations are not directly controlled in private lands and its hunting is forbidden in National Parks in Spain. Waiting for further research to evaluate the threshold of rabbit densities below which competitors and/or predators may prevent the recovery of rabbit populations, control of wild boars may be useful as a short-term strategy to recover small rabbit populations whenever it is linked to habitat improvements. [ABSTRACT FROM AUTHOR]

The endangered giant panda is the flagship species of wildlife conservation, a status that results in heightened attention to their well-being. However, one factor that hinders the ability to monitor this species in the wild is the difficulty to measure relevant physiological parameters which quantify the survival status in conservation research. In this study, we employed a non-invasive sampling method and immunochemical assays to determine if measurement of fecal steroid hormones is a viable option in monitoring the sex ratios and stress levels of a giant panda population. The results indicate that 1) the yearly concentration of fecal testosterone is a possible biomarker for distinguishing gender, and 2) invasive methods of artificial insemination and semen collection as well as parturition, cause an increase in fecal cortisol concentration. This study suggests that the noninvasive sampling of feces can be a practical tool to monitor physiological stress in free-ranging and fenced giant panda populations, and could be useful in the forthcoming giant panda census in determining sex ratios in the wild. [ABSTRACT FROM AUTHOR]