Flight performance and wing morphology in the bat Carollia perspicillata: biophysical models and energetics.

Studies on functional performance are important to understand the processes responsible for the evolution of diversity. Morphological trait variation within species influences the energetic cost of locomotion and impacts life history traits, with ecological and evolutionary consequences. This study examined wing morphology correlates of flight performance measured by energetic expenditure in the Seba's short-tailed bat, Carollia perspicillata. In the flight experiments, nature caught bats (59 females, 57 males) were allowed to fly for 3 min in a room. After each flight, thermographic images were taken to measure body temperature, and biophysical models were used to calculate sensible heat loss as a measure of energetic expenditure. Wing morphological traits were measured for each individual and associated with heat loss and power required to fly on performance surfaces. Wing morphological traits explained 7-10% of flight energetic cost, and morphologies with the best performance would save the energy equivalent to 9-30% of total daily requirements. The optimal performance areas within the C. perspicillata morphospace were consistent with predicted selection trends from the literature. A trade-off between demands for flight speed and maneuverability was observed. Wing loading and camber presented sexual dimorphism. These morphological differences are likely associated with more economical but less maneuverable flight in females, leading them to fly more often in open areas along the forest edge. Our findings demonstrate how small scale changes in wing morphology can affect life history strategies and fitness.

Habitat amount partially affects physiological condition and stress level in Neotropical fruit-eating bats.

Hematological measures are increasingly being used to analyse the impact of several stressors on the physiological condition of animals. Landscape degradation and habitat loss impacts terrestrial and volant mammals occurrence, however rarely the effects of these factors on physiological conditions and stress levels were analyzed. Here, we measured several hematological parameters to analyse the impacts of habitat amount on the physiological condition (body condition and health status) and stress level of four species of Neotropical fruit-eating bats. We measured hematocrit, hemoglobin concentration and calculated the hemoglobin-hematocrit residuals (HHR) and mean cell hemoglobin concentration (MCHC), as well as the neutrophil to lymphocyte ratio (N/L ratio) of four common frugivores bat species (Artibeus lituratus, Artibeus planirostris, Sturnira lilium and Carollia perspicilatta). The bats were captured in 20 landscapes within the Atlantic Forest biodiversity hotspot, in a gradient from 10 to 85% of habitat amount. We tested the influence of habitat amount, species, sex and reproductive condition on the physiological variables. We fit GLM to each of the response variables and performed a model selection to identify the most plausible to explain the patterns. N/L ratio was negatively influenced by habitat amount, while the other variables were not related to habitat amount. Overall, we found that habitat loss apparently did not jeopardize the physiological condition of fruit-eating bats and that stress level apparently is not high enough to have any deleterious effect. We suggest that the increase in glucocorticoids, indirectly assessed by the N/L ratio, is a predictive, beneficial response, that allow these bats to cope efficiently with the stressors associated with habitat loss.