Second-growth and small forest clearings have little effect on the temporal activity patterns of Amazonian phyllostomid bats

Secondary forests and human-made forest gaps are conspicuous features of tropical landscapes.Yet,behavioral responses to these aspects of anthropogenically modified forests remain poorly investigated.Here,we analyze the effects of small human-made clearings and secondary forests on tropical bats by examining the guild-and species-level activity patterns of phyllostomids sampled in the Central Amazon,Brazil.Specifically,we contrast the temporal activity patterns and degree of temporal overlap of 6 frugivorous and 4 gleaning animalivorous species in old-growth forest and second-growth forest and of 4 frugivores in old-growth forest and forest clearings.The activity patterns of frugivores and gleaning animalivores did not change between old-growth forest and second-growth,nor did the activity patterns of frugivores between old-growth forest and clearings.However,at the species level,we detected significant differences for Artibeus obscurus(old-growth forest vs.second-growth)and A.concolor(old-growth forest vs.clearings).The degree of temporal overlap was greater than random in all sampled habitats.However,for frugivorous species,the degree of temporal overlap was similar between old-growth forest and second-growth;whereas for gleaning animalivores,it was lower in second-growth than in old-growth forest.On the contrary,forest clearings were characterized by increased temporal overlap between frugivores.Changes in activity patterns and temporal overlap may result from differential foraging opportunities and dissimilar predation risks.Yet,our analyses suggest that activity patterns of bats in second-growth and small forest clearings,2 of the most prominent habitats in humanized tropical landscapes,varies little from the activity patterns in old-growth forest.

Trophic niche changes associated with the eradication of invasive mammals in an insular lizard: an assessment using isotopes

Invasive species are a major threat to island biodiversity,and their eradications have substantially contributed to the conservation of island endemics.However,the consequences of eradications on the trophic ecology of native taxa are largely unexplored.Here,we used the eradication of invasive black rats Rattus rattus and European rabbits Oryctolagus cuniculus from the Berlenga Island,in the western coast of Portugal,as a whole-ecosystem experiment to investigate the effects of the eradication of invasive mammals on the trophic niche and body dimensions of the island-restricted Berlenga wall lizard Podarcis carbonelli berlengensis over a 2-year period.Our results suggest an expansion of the isotopic niche and an intensification of the sexual dimorphism of the lizard following mammal eradication.Additionally,we found considerable variability in isotopic niche across the island and detected evidence of sex-specific and season-modulated nutritional requirements of this threatened reptile.Our findings support that the eradication of 2 of the planets most problematic invasive vertebrates led to changes in the lizard trophic niche and sexual dimorphism in just 2 years.This suggests that the ecological pressuresfor example,prey availability and habitat structureto which lizards are exposed have substantially changed post-eradication.Our study emphasizes the scientific value of island eradications as experiments to address a wide range of ecological questions and adds to the increasing body of evidence supporting substantial conservation gains associated with these restoration interventions.