Current knowledge about social behavior of free-ranging domestic dogs is scarce, and the possibility that they could form stable social groups has been highly debated. We investigated the existence of a social-dominance hierarchy in a free-ranging group of domestic dogs. We quantified the pattern of dyadic exchange of a number of behaviors to examine to what extent each behavior fits a linear rank-order model. We distinguished among agonistic dominance, formal dominance, and competitive ability. The agonistic-dominance hierarchy in the study group shows significant and substantial linearity. As in random assortments of captive wolves, there is a prominent but nonexclusive male agonistic dominance in each age class. The agonistic rank-order correlates positively and significantly with age. Submissive–affiliative behavior fulfills the criteria of formal submission signals; nevertheless, it was not observed among all dogs, and thus, it is not useful to order the dogs in a consistent linear rank. Agonistic-dominance relationships in the dog group remain stable across different competitive contexts and to the behaviors considered. Some individuals gain access to food prevailing over other dogs during competitions. Access to food resources is predicted reasonably well by agonistic rank order: High-ranking individuals have the priority of access. The findings of this research contradict the notion that free-ranging dogs are “asocial” animals and agree with other studies suggesting that long-term social bonds exist within free-ranging dog groups.

Paternity was analysed in two domestic cat (Felis catus) populations differing in habitat structure (rural versus urban) and density (234 cats km^-2 versus 2091 cats km^-2). A total of 312 offspring, 76 mothers and 65 putative fathers were typed at nine microsatellite loci in the two populations. Our data showed a high rate of multiple paternity in the urban population (70 to 83% of litters with more than one father), whereas it was much lower in the rural population (0 to 22% of litters with more than one), as most males were able to monopolize the entire litter. However, males reproduced as soon as they reached sexual maturity (i.e. ten months of age) in the urban population, whereas most males delayed reproduction to age three years in the rural population.