Influência das características da vegetação e altura do ninho sobre os riscos de predação de ovos em sub-bosque da floresta tropical atlântica.

Abstract

The risk of predation is a dynamic spatial-temporal process in which each habitat may represent a greater or lesser risk to prey. For birds, the characteristics of the habitat in which nests are located play a critical role in the intensity of predation. These characteristics include nest visibility and predator access ease. However, little is known about activity patterns and nest-searching strategies by predators. To understand these possible patterns, such as the total foliage hypothesis, the nest height hypothesis, and the specific predator hypothesis need to be taken into account. Thus, this study aimed to investigate the influence of vegetation characteristics, nest location, and predator type on the predation risk of understory bird nests in the Atlantic Forest, using natural nests with artificial eggs distributed at different heights and considering habitat variables such as litter, canopy, and vegetation density. Our results showed that mammals were the main nest predators, especially those on the ground and those located two meters high with low canopy coverage. On the other hand, birds presented a higher probability of predation in nests with higher vegetation density without a relationship with height. Understanding the predator assembly and potential reasons behind variations in nest predation rates is crucial to developing effective conservation strategies in complex environments and threatened systems.