Foxes and goats: the outcome of free-ranging livestock farming in Brazilian dry forests

Humans are promoting drastic changes in biological communities that result in 'winner-loser' species replacements across multiple spatial scales. In tropical regions, such replacements can be particularly driven by deforestation, especially in landscapes devoted to free-ranging livestock production in which mixing native and exotic species can create species-poor and homogenized communities. We tested this hypothesis assessing medium- and large-bodied non-volant mammals in four 16-km(2) landscapes with varying deforestation levels (5%, 30%, 70%, and 95% forest cover), where exotic mammals (e.g., cows and goats) have free access to the remaining Caatinga dry forest. Using camera traps, we obtained 2808 independent records of 17 species, most of them (2054 records, 73%) corresponding to seven exotic species. Native Cerdocyon thous (crab-eating fox) and exotic Capra hircus (goat) accounted for almost half of the records and 60-80% of the records in the two most deforested landscapes. Alpha diversity did not differ significantly among landscapes, but the two more forested landscapes tended to have more native species than exotic ones. Beta diversity patterns among and within landscapes were relatively low regardless of species abundance, indicating biotic homogenization at multiple spatial scales. We conclude that a novel mammal community full of exotic mammals and a few generalist natives has been established in the study region. To promote environmental-friendly livestock farming in the largest tropical dry forest of South America, we should avoid deforestation, especially in sites that concentrate native species, segregate lands for livestock and conservation, and boost inspection against illegal hunting.

Automated summary

Humans are causing significant changes in biological communities, particularly through deforestation in tropical regions. This study found that deforestation and the mixing of native and exotic species in livestock production landscapes have led to the establishment of species-poor and homogenized communities, dominated by exotic mammal species. The study highlights the importance of avoiding deforestation, segregating lands for livestock and conservation, and strengthening the enforcement against illegal hunting to promote environmentally-friendly livestock farming in the region.