Social dominance is widely known to facilitate access to food resources in many animal species such as deer. However, research has paid little attention to dominance in ad libitum access to food because it was thought not to result in any benefit for dominant individuals. In this study we assessed if, even under ad libitum conditions, social rank may allow dominant hinds to consume the preferred components of food. Forty-four red deer hinds (Cervus elaphus) were allowed to consume ad libitum meal consisting of pellets of sunflower, lucerne and orange, and seeds of cereals, corn, cotton, and carob tree. The meal was placed only in one feeder, which reduced accessibility to a few individuals simultaneously. During seven days, feeding behavior (order of access, time to first feeding bout, total time spent feeding, and time per feeding bout) were assessed during the first hour. The relative abundance of each meal component was assessed at times 0, 1 and 5 h, as well as its nutritional composition. Social rank was positively related to the amount of time spent feeding during the 1st h (P = 0.048). Selection indices were positively correlated with energy (P = 0.018 during the 1st h and P = 0.047 from 1st to 5th) and fat (only during the 1st h; P = 0.036), but also negatively with certain minerals. Thus, dominant hinds could select high energy meal components for longer time under an ad libitum but restricted food access setting. Selection indices showed a higher selectivity when food availability was higher (1st hour respect to 1st to 5th). Finally, high and low ranking hinds had longer time per feeding bout than mid ones (P = 0.011), suggesting complex behavioral feeding tactics of low ranking social ungulates.
26 March 2011 in Behavioral Ecology and Sociobiology
Fighting between males is a frequent component of the rutting behavior of Cervidae. Frequent conflicts are exhausting; fighting may be risky and can lead to serious injuries or even death. We focused on the process of assessment of the opponent's fighting ability and escalation of the combat, estimating the probability of fighting based on the encounter components such as groaning and parallel walk. In this study, we observed the agonistic behavior of fallow deer bucks (Dama dama) during the rut over four seasons. During this time, we recorded 205 encounters between bucks. Non‐contact display, which allows contestants to assess their opponents fighting ability, occurred in 83% of the encounters. The highest predicted probability of a fight was found when both of the males vocalized and turned into the parallel walk. The chance of a clear outcome decreased when the males were fighting in comparison to when they did not fight. The initiator of the competitive encounter won 41% of the cases, while the attacked buck won 23% of the encounters. If the contestants avoided fighting, however, the initiator won 78% of encounters. Therefore, the initiator was more successful when no fight occurred compared to when the encounters escalated into fighting. In most cases where ritualized behavior occurred, one of the opponents left after vocalization or parallel walk occurred. Thus, vocalization and parallel walk increased the probability for a clear outcome. The probability of a fight was lowest in situations where the males displayed asymmetric behavior. Increased symmetry of the contestants' behavior was strongly correlated with a higher probability of a fight. Thus, these results indicate that fallow deer bucks use efficient tactic during the rut, which, in turn, minimizes the chance of injury while fighting during the breeding season. Aggr. Behav. 33:7–13, 2007.