Microhabitat Use by the Invasive Green Anole, Anolis carolinensis, and Native Lizards on Zamami-jima Island, Ryukyu Archipelago, Japan

Abstract

This study aimed to clarify microhabitat use by the invasive green anole, Anolis carolinensis and four native lizard species on Zamami-jima Island, Japan. Daytime and nighttime field surveys were conducted at sites with (GAP) and without A. carolinensis (GAA). At the GAP sites daytime use of plant species, substrates and perch height by A. carolinensis differed from native lizards, whereas the parts of plants used by A. carolinensis were similar to those used by native lizards. The perch substrate types (plant parts, ground or artificial substrates) used by native lizards during the daytime differed slightly between the GAP and GAA areas. During the night, the resting plant species used by A. carolinensis differed from those used by the native lizards at the GAP area, although the plant parts and height above ground were similar to those used by the native lizards at the GAP area. In particular, Takydromus smaragdinus used Pennisetum purpureum leaves at a high frequency as a resting place in the GAA area. In contrast in the GAP area T. smaragdinus was never found resting on P. purpureum leaves while 77% of A. carolinensis were found resting on P. purpureum. These findings suggest that the overlap of microhabitats between A. carolinensis and native lizards is small during the daytime, but that this invasive lizard species influences the selection of resting sites by T. smaragdinus. Further studies are required to understand how A. carolinensis may exclude T. smaragdinus from resting sites.