Social Behavior of the Maned Wolf (Chrysocyon brachyurus) and Bush Dog (Speothos venaticus): A Study in Contrast

Social behavior of the maned wolf, Chrysocyon brachyurus, and bush dog, Speothos venaticus, was compared. Differences in communication mechanisms between these two South American canids could be correlated with their social organization and ecology. Chrysocyon, inhabiting the savannahs of South America and feeding primarily on small vertebrates, invertebrates, and fruit, exhibits a dispersed social system, that is, it is essentially solitary in habit. The maned wolf relies primarily on signals that carry well over long distances and tend to promote the spacing of individuals through avoidance (for example, the bark), a conspicuous visual threat display, and locus-specific defecation. By contrast, Speothos is a cooperative hunter of the Neotropical rainforest, feeding mainly on rodents that are large relative to its own size. It is social and mainly employs short-distance signals, which promote approach behavior (tail-wagging), reduce intraspecific aggression (displays of active submission), and allow the maintenance of constant contact in the forest (the squeak vocalization). Quantitative observations on urine-marking suggest that the frequency of marking in Chrysocyon is partly dependent on the amount of available space, whereas in Speothos, marking may be influenced by social factors.