Living fences decrease the edge effect on nest predation in a tropical dry forest landscape: evidence from an experiment using artificial nests

Agricultural expansion has contributed to the loss and fragmentation of natural habitats and, as a consequence, the edge effect in these habitats has increased, leading to nest predation rates higher at the edge of fragments than in the interior. Living fences in abandoned croplands, however, add a structural component to the landscape which can help to mitigate the effects of disturbance. We used artificial nests to assess whether a living fence at the edge of a fragment of tropical dry forest, immersed in an agricultural landscape, can assuage the edge effect by decreasing predation rates. We identified the predators that attacked nests at several distances from the living fence and related the frequency of predator attacks with plant height, leaf height diversity, and tree and herb coverage. Vegetation structure of the living fence was vertically more complex than that found inside the fragment. 52% of nests were predated and we did not find a significant relationship between predation rates and the proximity of nests to the living fence, suggesting a null edge effect on predation. Birds were the most frequent predators, followed by rodents and carnivorous mammals, with the composition of predators varying among transects. The composition of predators and vegetation structure of the living fence were the factors that explained the null edge effect on nests predation. Our results indicate that the presence of a living fence at the edge of a fragment in agroforestry systems could mitigate the edge effects on nest predation.