A preliminary systematic review of the impact of cats on wildlife in the Neotropics

Cats are an invasive alien species that can negatively affect wildlife. However, information regarding their impact on Neotropical wildlife is scattered and limited. We conducted a systematic review to identify studies specifically exploring the impact of cats on wildlife in the Neotropics. In particular, we aimed: 1) to identify the temporal evolution of studies on the impact of cats, as well as bias and gaps that have occurred as a result of their spatial distribution (per country) and the typology of their impact; 2) to identify the Neotropical wildlife species directly affected by cat predation and to categorize these according to their taxonomic groups; 3) to describe the research techniques employed; and 4) to compare the environments evaluated (urban, rural, natural, mixed), as well as the different categories of cats (feral, stray, owned, mixed) involved. We found a total of 55 studies conducted in seven Neotropical countries, with Brazil presenting the most research, but found no research at all in 26 countries. Evaluation of pathogens in cats was the main topic addressed. In total, 215 taxa were reported to be affected by cat predation, with birds being the most frequent. Nine techniques were used in these studies, with blood analysis presented as the most commonly used methodology. Owned cats in urban environments were the most frequently evaluated, and stray cats in mixed environment were the least frequently evaluated. Our results show that cats have a significant negative effect on Neotropical wildlife, and increased studies are therefore a priority.