We expected that adult females would emerge earliest as early parturition
increases juvenile survival. We predicted that females with large fat stores should emerge earliest because of their ability to tolerate inclement spring weather at the maternity roost. We also predicted that adult males would remain active later than females to maximize mating opportunities and compensate for body mass decline during the Sirolimus cost mating period. We implanted 475 bats with PIT tags and remotely recorded immergence and emergence timing at a hibernaculum in central Canada. As expected, adult males were active significantly later (median immergence date = 16 September 2011) than adult females (11 September 2011) and adult females emerged earlier (median emergence date = 6 May 2012) than both adult males (25 May 2012) and subadults (13 May 2012). Emergence timing was correlated with fall body condition in adult females, with fatter females emerging earlier, but not males. Our results highlight the importance of reproductive timing as an influence on hibernation phenology of mammals.
“Department of Anatomy and Cell Biology, Oklahoma State University Center for Health Sciences, Tulsa, Oklahoma, USA Interspecific adult bite forces for all extant crocodylian species are now known. However, how bite forces scale during ontogeny across the clade has yet to be studied. Here we test the hypotheses that extant crocodylians share positively allometric and statistically comparable developmental scaling coefficients for maximal bite-force Selleck ICG-001 capacity relative selleck chemical to body size. To do this, we measured bite forces in the Australian freshwater crocodile Crocodylus johnsoni and the Saltwater crocodile C. porosus, and determined how performance changed during ontogeny. We statistically
compared these results with those for the American alligator Alligator mississippiensis using 95% prediction intervals and interpreted our findings in a phylogenetic context. We found no observable taxon-specific shifts in the intraspecific scaling of biomechanical performance. Instead, all bite-force values in our crocodylid dataset fell within the bounds of the A. mississippiensis 95% prediction intervals, suggesting similar bite-force capacity when same-sized individuals are compared. This holds true regardless of differences in developmental stage, potential adult body size, rostro-dental form, bone mineralization, cranial suturing, dietary differences or phylogenetic relatedness. These findings suggest that intraspecific bite-force scaling for crocodylians with feeding ecologies comparable with those of extant forms has likely remained evolutionarily static during their diversification.