Contreras, G.; Peredo, R.; Sandvig, E. M.; Rodriguez, B.; Gallardo, B.; Norambuena, H. V.; Medrano, F.

Free-ranging domestic dogs can cause numerous negative impacts on public health, tourism, and the environment. Some of these impacts on wildlife are compounded and facilitated by human communities, for example through the provision of food, health care, and shelter, which altogether increase the dog\'s life expectancy. Shorebirds are one of the groups adversely affected by dogs through nest predation, behavioral changes, and persecution during foraging and roosting periods. In Chile, dogs are a ubiquitous threat in wetlands. In this study, we characterized the dog populations at the mouth of the Lluta River (Chacalluta area) and the Coihuin wetland (Coihuin-Chamiza area), both of international importance for shorebirds. We estimated the total abundance of dogs, their seasonal survival, and demographic and behavioral traits by photographic capture-recapture methods in eight surveys of 6.6 km2 for Chacalluta and 2.0 km2 for Coihuin-Chamiza. We estimated a population size of 167 individuals in Chacalluta and 505 individuals in Coihuin-Chamiza, a relatively low survival rate in both sites, a healthy body status in more than 80% of the dogs, small group sizes (1-2 individuals), and movements of 1,000 to 3,000 meters between locations. We report patterns associated with human ownership, indicating irresponsible pet ownership. This information will be the basis for developing public policies and evaluating strategies to lessen their impact on shorebirds, such as demographic control of the animal population, reduction of abandonment, and promotion of responsible pet ownership practices.