Vigilance behavior may directly affect fitness of prey animals, and understanding factors influencing vigilance may provide important insight into predator-prey interactions. We used 40,540 pictures taken withcamera traps in August 2011 and 2012to evaluate factors influencing individual vigilance behavior of white-tailed deer (Odocoileus virginianus) while foraging at baited sites. We used binary logistic regression to determine if individual vigilance was affected by age, sex, and group size. Additionally, we evaluated whether the time of the day,moon phase,and presence of other non-predatorwildlife species impacted individual vigilance. Juveniles were 11% less vigilant at baited sites than adults. Females were 46% more vigilant when fawns were present. Males and females spent more time feeding as group size increased, but with each addition of 1 individual to a group, males increased feeding time by nearly double that of females. Individual vigilance fluctuated with time of day andwith moon phase but generally was least during diurnal and moonlit nocturnal hours, indicating deer have the ability to adjust vigilance behavior to changing predation risk associated with varyinglight intensity.White-tailed deer increased individual vigilance when other non-predator wildlife were present. Our data indicate that differential effects of environmental and social constraints on vigilance behavior between sexes may encourage sexual segregation in white-tailed deer.
The float test is the most widely used method to discriminate between viable and nonviable acorns. It provides an objective, simple, rapid, and inexpensive test to inform experiments and management strategies dependent on quantification of viable acorns. However, the accuracy of the float-test method is understudied. To test the accuracy of the float-test method, during autumn of 2013 we collected 300 acorns from white oak (Quercus alba), native to our study area within the city limits of Raleigh, North Carolina, USA, and sawtooth oak (Q. acutissima), not native to the study area. An untrained observer visually inspected acorns (visual test) to assign viability subjectively and then float-tested the respective acorn. After conducting visual and float tests, we planted the acorns in a test plot protected from predation. In the test plots, 56% of white oak acorns and 60% of sawtooth acorns germinated. Both the float test and visual methods accurately predicted viability in both oak species. However, the visual test (white R 2 ¼ 0.83, sawtooth R 2 ¼ 0.85) explained more variation in observed germination than the float test explained (white R 2 ¼ 0.65, sawtooth R 2 ¼ 0.70). Our data indicate the float test, though objective, is less accurate than an untrained observer at predicting the viability of acorns. We tested the potential for the methods to be paired to further improve prediction accuracy and determined the float test provided no additional information to visual inspections. When dissecting or germinating acorns is not possible, our data indicate that visually inspecting acorns is better than float-testing to determine viability. Ó 2017 The Wildlife Society.
Theories describing the role of antlers in reproductive biology have lacked substantive evaluation due to the inability to differentiate the effects of antler size from other allometrically related morphological traits. We developed an antler manipulation technique to facilitate comparisons of antler size while controlling for body size and age using white‐tailed deer Odocoileus virginianus. We describe the process by which antlers can be manipulated to further investigate the functions of antlers. We believe this process is a viable option for manipulating antler size across Cervidae with appropriate modification to scale.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.