A comparison of Mediterranean Gecko (Hemidactylus turcicus) populations in two temperate zone urban habitats

Abstract

Urban ecosystems represent unique habitats that might be more or less suitable than natural systems for many species. The Mediterranean Gecko, Hemidactylus turcicus is a synanthropic species that has successfully colonized many urban and suburban areas outside its natural range. In the United States, H. turcicus has been found predominantly in southern states on exterior surfaces of buildings. We compared population density, demographics, and extent of dispersal of populations of H. turcicus at two anthropogenic sites in a temperate region of the United States. The University of Central Oklahoma (UCO) had higher building density and greater cover by anthropogenic surfaces and the Oklahoma City Zoo (ZOO) had lower building density and greater cover by vegetation. Mark and recapture sampling was conducted at UCO from 2006 to 2007 and during 2008 at ZOO. The sizes of the populations at the two sites were estimated using the Schnabel method and population densities were calculated using those estimates. Age class of captured animals, sex of adults, and gravid status of adult females were determined at both sites. We assumed that greater exterior wall surface area of individual buildings at UCO and greater land cover by anthropogenic surfaces might 1) reduce population density and 2) facilitate dispersal there relative to the ZOO. Population sizes and density in animals per ha of land and building cover and demographics were similar at the two sites. Population density per ha of building exterior wall area was higher at ZOO than at UCO. The higher density of animals on buildings, lower proportion of subadults in the population and lower maximum dispersal distance at ZOO suggest that successful diffusion dispersal might be limited at that site relative to UCO.