The impacts of domestic dogs (Canis familiaris) on wildlife in two Brazilian hotspots and implications for conservation

Abstract

Exotic species are major threats to biodiversity worldwide. Domestic dogs (Canis familiaris) are among the most common invasive predators in the world, interacting with wildlife in many ways. We present ecological data based on camera traps and occasional observations of free–roaming domestic dogs from localities within the Brazilian Atlantic forest and Cerrado hotspots. Canis familiaris was the second most abundant mammal species, and the most abundant carnivore. Dogs chased, killed, and/or competed with at least 26 native species. They consumed none of the killed animals, which together with the predominant records of solitary individuals acting during the daytime indicates they are mainly free–roaming dogs relying on humans for food and shelter. The high numbers of dogs and the wide range of prey suggest wildlife could be greatly impacted by domestic dogs, especially in areas that are highly threatened by anthropogenic activities, such as biodiversity hotspots. We highlight possible measures (such as the eradication or removal of dogs from natural areas) that could help to reduce the environmental damage caused by domestic dogs in the region.