Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Ecology of the synanthropic Mediterranean House Gecko (Hemidactylus turcicus) at their northern invasion front.

Abstract

Invasive herpetofauna are a significant threat to native wildlife and when colonizing higher latitudes, they must cope with greater seasonality that likely exposes them to temperatures below their preferred temperature range and reduced physiological performance. Therefore, it is important to understand the ecology of invasive herpetofauna along their invasion front as this is the point they face the most disparate climates to their invasive range core. We studied a population of Mediterranean House Geckos (Hemidactylus turcicus) that recently colonized an urban center in southern Illinois, a region that experiences greater seasonality than their native or invasive range. We surveyed buildings for H. turcicus in September 2019 and May - October 2020 and recorded a variety of ecological variables including body length, body and environmental temperature, sex, and reproductive status. Despite experiencing and remaining active in temperatures 6°C below their preferred range for multiple months, H. turcicus appeared to exhibit no negative consequences as the population displayed similar growth rates and clutch frequency found in the southern core of the invasive range.. We also found that H. turcicus randomly selected marginally warmer microhabitats with respect to what was available indicating temperature may not be an important determinant of their microhabitat selection. Our results indicate that H. turcicus can persist at higher latitudes with little apparent costs to their physiological performance, and population demographics suggesting their inherent eurythermic nature and synanthropic nature enables them to rapidly colonize novel habitats regardless at this northern latitude.