Use of naturally and anthropogenically disturbed habitats in Amazonian rainforest by the teiid lizard Ameiva ameiva

We studied the effects of natural and anthropogenic habitat disturbances on environmental temperatures and their consequent effects on thermoregulatio n and habitat use of Ameiva ameiva in a complex habitat matrix of primary t ropical forest and several types of disturbed forest in Amazonian Brazil. D ata on Ameiva ameiva from other regions in Brazil with habitats that have l ittle canopy coverage are compared with data from rain forest sites to dete rmine if activity of rain forest Ameiva is temporally or spatially limited by the thermal opportunities available in shaded environments. Ameiva ameiv a preferentially used disturbed habitats in rain forest regions. These site s had significantly higher environmental temperatures than did surrounding undisturbed rain forest. Environmental temperature distributions indicate t hat the closed canopy rain forest is a thermally marginal habitat for Ameiv a ameiva and that high temperatures resulting from forest clearing are like ly to enable Ameiva ameiva to increase foraging activity in adjacent forest edges above what is possible in the continuous interior forest. Ameiva ame iva from rain forest, cerrado and savanna regions of Brazil had significant ly lower body temperatures than Ameiva from caatinga, an open habitat type with little canopy coverage. This difference is probably due to high ambien t temperatures and the high availability of basking sites in open habitats and suggests a thermal constraint on habitat use and time of activity for A meiva in closed canopy habitats. (C) 1999 Elsevier Science Ltd. All rights reserved.