Avoidance behaviors of pray species to the odors of predators are effective to avoid predation, however, the behaviors are accompanied with costs. The avoidance occurs toward fur, feces, urine, and anal gland secretions of predators. Many studies have focused on small animals (e.g. rodents) as prey species and carnivores as predator species (e.g. cats). However, for large sized mammals, all carnivora species are not necessarily their predators. Can large sized pray species distinguish their true predators by the odors? We focused on sika deer Cervus Nippon, which is a large sized herbivore in Japan. We conducted a feeding test with potable feeders. Bait was provided to sika deer with odors of feces of,two non-native predators (lion and wolf), and feces of 11 middle or large sized native mammals (one Lagomorpha, one Primates, three Artiodactyla, and six Carnivora). Within six carnivora, only Japanese red fox and Asian black bear can be potential predators for sika deer. We also measured the volatile components of the feces of all the above 13 mammals by gas chromatography. We conducted a nMDS analysis to reveal the similarity of the volatile components of the feces among the study species.
Results/Conclusions
Sika deer did not eat or escaped from the feeders when they sniffed the odors of feces of all the eight carnivora species and Japanese macaque. Four native carnivora species and Japanese macaque do not prey on sika deer, however, the rates of the avoidance of sika deer to the odors of these six animal feces are not clearly different from those to the odors of the feces of lion, wolf, Japanese red fox, and Asian black bear. From the results of gas chromatography, the feces of all the carnivora species and Japanese macaque have the similar compositions of the volatile components. These results suggest that sika deer avoid not only its predators but also small carnivora species and Japanese macaque that do not prey on sika deer because the volatile components of the feces of these animals are similar to the predator of sika deer. Therefor we propose that sika deer escapes from its non-predator, although these behaviors may cause adaptive disadvantages through interruption of foraging behavior and/or useless consumption of energy.