Free-Ranging Dogs and Wildlife Conservation. Edited by Matthew E. Gompper © Oxford University Press 2014. Published 2014 by Oxford University Press. dogs with sympatric carnivores will depend on their position in the interference hierarchy, with dogs being either at the receiving or giving end of aggressive interactions, or both. 2. Dependence on human-derived food: Interfer- ence competition may be seen ultimately as a function of food acquisition. Although most dog populations are heavily dependent on human- derived food (HDF), this is variable depend- ing on their degree of association with humans. Dogs in urban areas are almost completely de- pendent on HDF, whereas at the other extreme, wild dogs (such as the dingo) and feral dogs are fully dependent on wild-caught food (Vanak and Gompper, 2009b). Thus, it can be assumed that competition with wild carnivores is likely high- est in areas where dependence on wild resources is highest. 3. Population density: The competitive effects of dogs can also be inluenced by their density and their tendency to form packs. Even without hu- man involvement, packs of dogs are capable of overpowering not just herbivores several times their size (Corbett, 1995), but also carnivores such as foxes, coyotes, and jackals (Vanak and Gompper, 2009b; Van Sittert, 1998). Furthermore, numerical superiority can improve competitive- ness in obtaining resources such as carcasses. Thus, competitive ability may be a function of density at the local scale. 3.1 Introduction In many natural and semi-natural systems world- wide, dogs ( Canis familiaris) are an integral part of the carnivore community (Gompper, Chapter 1). Until recently, the role of dogs as mid-sized mem- bers of the carnivore guild, and how they shape the structure of native carnivore communities, has garnered little attention. Of late, however, a suite of studies across the world has highlighted several key aspects of the competitive dynamics that occur between dogs and sympatric members of the car- nivore community (Table 3.1). These studies have demonstrated that dogs often compete with native carnivores for food, and that smaller carnivores may react to dogs as they would to any other mid- sized predator: with increased vigilance, lowered food intake, avoidance of dog-dominated habitat types, or complete spatial separation. These studies have also shown that the types and intensity of in- teractions between dogs and subordinate predators are likely inluenced by several factors, including, but not limited to: 1. Relative position within the native carnivore community: In several areas dogs are the largest mammalian carnivore and hence assume the role of the apex predator (e.g., Australasia), whereas in others they may be part of a guild of carnivores where they occupy a mesopredator position (e.g., India, Africa). The nature of the interactions of CHAPTER 3 Top-dogs and under-dogs: competition between dogs and sympatric carnivores Abi Tamim Vanak, Christopher R. Dickman, Eduardo A. Silva-Rodriguez, James R.A. Butler, and Euan G. Ritchie 04-Gompper-Chap03.indd 69 04-Gompper-Chap03.indd 69 14/09/13 9:34 AM 14/09/13 9:34 AM