Your best friends can be your worst enemies: impact of domestic cats and dogs in megadiverse countries

Domestic cats and dogs are the most beloved human pets. As a result, they have become globally invasive species and are the most abundant carnivores in the world. Although they have a good relationship with humans, domestic cats and dogs have a negative ecological impact with significant consequences for conservation policies worldwide. The effects of these animals on wildlife have been studied only in a few countries, with most studies carried out in countries or regions with low vertebrate biodiversity (USA, New Zealand, and Europe). Except for a few studies carried out in Australia, Brazil and Mexico, we have no information on the effects of these predators in megadiverse countries. The main negative environmental effects of both species include predation of vertebrates and invertebrates, competition for food and space with native fauna, hybridization with phylogenetically close species or wild populations of their species, and transmission of diseases to wildlife and humans. The lack of information on the effects that introduced predators have at continental scales and the false perception of the human population that cats and dogs do not adverse impacts on the environment difficult their management and control. It is crucial to increase the number of studies of these two species in megadiverse countries to propose adequate management strategies that promote the conservation of native fauna.