The Ecology of Free-Roaming Domestic Dogs in Rural Villages near Serengeti National Park in Tanzania

Free-roaming dogs, Canis lupus familiaris, can be both a public health and conservation concern. Between 2010 and 2013 we identified 2,649 dogs in four rural villages in Tanzania. We characterized dog demography and ownership practices and investigated whether vaccination influences dog population dynamics. We found that adult dogs had higher survival than puppies in all villages. We observed a male-biased sex ratio across all age classes and higher adult male dog survival. Within the vaccination villages, vaccinated dogs had a decreased risk of death. However, overall mortality in one non-vaccination village was significantly higher than in the two vaccination villages and other non-vaccination village. Dogs in poor body condition had lower survival than dogs in ideal body condition in all villages. Sickness and spotted hyena, Crocuta crocuta, predation were the two main causes of dog death. Reproductive patterns were similar between vaccination and non-vaccination villages and we observed an overall male-biased litter sex ratio regardless of the mother’s body condition. Dogs were owned and used primarily for livestock and household protection. We found that dog ownership was related to livestock ownership, household size, education, and house type. Thus, the number of dogs increases with household wealth. Stable isotope analyses of dog hair confirmed survey data and indicated that dogs were fed primarily a corn-based diet similar to human diet in the villages.Free-roaming domestic dogs in rural communities exist in the context of their human owners as well as the surrounding wildlife. Our results demonstrate that vaccination alone does not impact domestic dog population dynamics and that they may be mediated by humans. Understanding the role of dogs and their care within these communities is important for planning and implement rabies control measures such as mass dog vaccination.