Natural history traits influence winners and losers for herpetological communities in disturbed tropical habitats.

Abstract

Habitat alteration can lead to a few 'winning' species outcompeting many 'losing' species, an effect commonly termed as 'Winner-Loser-Replacements' or WLRs. This can lead to homogenisation of species assemblages at phylogenetic and functional levels. Most previous studies analyse responses of species abundance without considering natural history traits associated with those species. This study uses fourth corner modelling techniques to investigate the interaction between ecological data and natural history trait information using a herpetofaunal assemblage that includes 19 species of amphibians, 28 snakes, and 20 lizards, in Parque Nacional Laguna del Tigre, Guatemala. A total of 120 transects were surveyed using Visual Encounter Surveys, comprising 18 in disturbed habitat, 66 in forest habitat, and 36 in edge habitat respectively. Overall, greater diversity of ecological traits was revealed in forest and edge habitats compared to disturbed habitats at the forest edge close to agricultural land. Models revealed that for amphibians (Hypopachus variolosus and Incilius valliceps) and snakes (Coniophanes schmidtii and Leptodeira septentrionalis), association with bare ground, and in the case of amphibians, leaf litter, predicts species persistence in disturbed habitats. Continued forest fragmentation in the region will result in increased edge effects, and a greater proportion of forest remaining in an early successional state, leading to a highly reduced, homogenized, amphibian and reptile assemblage. Using such models for community assemblages of animals to reveal the identity of WLR patterns in forests with continued fragmentation is a useful tool to reveal which species are at risk of impact before habitats become degraded.