Traços da história de vida determinam as respostas populacionais e morfológicas de besouros rola-bostas a efeitos indiretos de fragmentação florestal

Abstract

Dung beetle life cycle and adult size depend on the resources provided from mammals, making them a group of associate species. This association makes dung beetle susceptible to the environmental disturbances experienced by mammals due cascading effects. In this work I investigated the direct and indirect effects of forest fragmentation on populational and morfological traits of four dung beetle species (Oxysternon conspicillatum, Deltochilum enceladus, Eurysternus caribaeus and Onthophagus rubrescens). I accessed the direct effects from the size, age and isolation degree of 20 forest remnants on the abundance, body size and secondary sexual traits of these four species. To determine the indirect effects of forest fragmentation I used mammal richness and biomass. I used path analysis to determine these effects. The results showed that two of the four species responded just the decline of mammals in fragments, therefore just indirectly. D. enceladus responded through populational reduction, and O. conspicillatum responded through body size reduction. The body size and abundance of E. caribaeus, O. rubrescens and the secondary sexual traits of O. conspicillatum and O. rubrescens did not respond to the metrics of this study. These results sugests that the differences in life-history traits like eventual tolerance of matrix, body size and reproductive strategy could influence the responses of species to environmental disturbances.