Assessing the effect of urbanization on tropical forest dwelling teiid lizards

Abstract

Urbanization causes marked changes in the landscape usually detrimental for wildlife. There is, thus, a pressing need to understand how wildlife respond to these changes. Here we evaluate the occurrence of large sized teiid lizards (Ameiva ameiva, Tupinambis marianae and Kentropyx calcarata) and the density of K. calcarata inhabiting urban and non-urban forest fragments. We address the question whether urbanization and fragment size influence population persistence and density. We expected that K. calcarata would be found at higher density in smaller fragments due to an abundance of resources and lower predation pressure. We conducted a survey of five urban fragments (range: 5–515 ha) and of one control non-urban fragment (over 1000 ha) of semi-deciduous Atlantic forest in Paraiba, NE Brazil. We surveyed a total of 44 transects and used distance sampling to estimate the density. We recorded a total of 61 K. calcarata with an estimated density of 3.76 ind/ha (95% CI: 3.0–4.65) in the urban fragment and 5.57 Ind/ha (95% CI: 3.7–8.3) in the non-urban fragment. Contrary to our expectations, K. calcarata was not observed in the small urban fragments nor were A. ameiva. In non-urban areas K. calcarata respond to fragmentation with a marked increase in abundance. Urban forest fragments are subject to several anthropogenic disturbances that could contributed to the decline and local extinction of teiid lizards. We suggest teiid lizards might be good indicators of environmental health in small urban forest fragments and monitoring of their population might provide information for management and conservation.