Percepção de predadores por Ololygon alcatraz (B. Lutz, 1973) (Anura, Hylidae) e implicações para sua conservação

Abstract

The biodiversity crisis is a global concern that has been motivating various conservation initiatives across different sectors of society. With increasingly severe implications for ecosystems, the importance of ex situ conservation, combined with in situ conservation efforts, is evident and has been yielding more positive results. There are still limitations in ex situ conservation, especially related to behavioral deficiencies observed in captive individuals. Naivety towards predators and other threats in the natural environment, as well as inefficient foraging abilities and difficulties in communicating with native conspecifics, are some of the crucial aspects that can directly impact the success of reintroduction. The ability to distinguish between predators and non-predators among heterospecifics is a basic component in threat assessment, with most predator recognition skills being chemically or visually oriented, often in combination. In the case of anurans, there is extensive literature on defensive behavior and predator perception, as well as ontogenetic variations between tadpoles and post-metamorphic individuals. Despite being the most threatened group of vertebrates and having a global effort to promote various ongoing conservation actions, ex situ conservation of anuran amphibians remains limited. Ololygon alcatraz is the first Brazilian target species for this type of program, a bromeliad-dwelling species endemic to Alcatrazes Island and critically endangered, part of the São Paulo Zoo's ex situ Conservation Program. The aim of this study was to assess the predator perception by Ololygon alcatraz and the interference that captive breeding may have on its behavior, intending to support possible reintroduction actions in the wild and deepen the ethological knowledge of the species for the conservation of the free-living population. Forty individuals were evaluated, fifteen from the wild and twenty-five under human care, exposed to chemical-visual stimuli of potential natural predators of the species. Our results indicate that, overall, under human care individuals showed a faster escape response to stimuli, while wild individuals more frequently chose not to move when exposed to stimuli. The most observed defensive strategy was immobility, followed by escape. There were no significant differences in responses to different predators. The behavioral variation between groups can be attributed to various factors, including adaptation to ex situ conditions, previous exposure to similar stimuli, and variations in environmental conditions.