Variation in reproductive traits of members of the genus Canis with special attention to the domestic dog (Canis familiaris)

We compare differences in the reproductive strategies of “free-living” dogs with their wild relatives in the genus Canis, of which the dog is a very recently evolved member. The members of this genus display a greater range of parental motor patterns than generally seen in other species of Carnivora, including pair-bonding and extended parental care; parents regurgitate to offspring and provision them with food for months to as long as a year. But the domestic dog does not routinely display these genus-typical behaviors. While this has generally been assumed to be a result of direct human intervention, humans have little reproductive control over the vast majority of domestic dogs. We analyze the low frequency of display of genus-typical behaviors and postulate that the dog’s reproductive behaviors are an adaptation to permanent human settlement and the waste resources associated with it. Adaptation to this environment has decreased seasonality, increased the fecundity of unrestrained dogs and reduced the need for prolonged parental care. The consequences of greater fecundity and reduced parental care are compared to the reproductive behavior of other species of the genus.