Geckos as Indicators of Urban Pollution

Geckos as Indicators of Urban Pollution

Dean E. Fletcher¹, William A. Hopkins², Michelle M. Standora¹, Carmen Arribas³, Jennifer A. Baionno-Parikh¹, Teresa Saldaña³, and Carlos Fernández-Delgado³

¹Savannah River Ecology Laboratory, University of Georgia, Drawer E, Aiken, South Carolina 29802, USA
²Department of Fisheries and Wildlife Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA
³Departamento de Zoologia, Edificio Charles Darwin, 3^a Planta, Campus Universitario de Rabanales, Universidad de Córdoba, Córdoba 14071, España (Spain)

Abstract: Geckos are common inhabitants of urban areas where they reside on manmade structures (e.g. building walls). Although their diets are generally opportunistic and include a variety of arthropods, foraging often occurs around artificial lights. The gecko's carnivorous diet and ability to adapt to urbanized conditions make them excellent organisms to study uptake and effects of urban pollution. We used the Moorish Wall Gecko (Tarentola mauritanica) to detect accumulation of trace elements in urban areas. Whole body accumulation was assessed for 15 elements (Be, Al, V, Mn, Ni, Cu, As, Se, Mo, Cd, Sb, Cs, Pb, U, and Tl). Accumulation was compared among three locations in southern Spain that represent a gradient in urbanization. Locations included a large city (Córdoba), a smaller town (Villaviciosa de Córdoba), and a rural area (Guadalmellato Reservoir). Multivariate analyses of element concentrations identified contaminants that increased with urbanization. This pattern was evident for Cs, V, Se, As, Ni, and Cd. However, Pb showed the most striking elevation in urban areas. Lead concentrations in geckos from the city were 15 times that of those from the rural site, exceeding those known to impose toxicological effects on wildlife. Comparison of element accumulation in the tails of geckos with whole body concentrations also revealed the utility of tail clips as a nondestructive index of contaminant uptake. We conclude that in areas where abundant, geckos represent useful taxa to study the bioavailability and effects of several environmentally important urban pollutants.

Keywords: Bioindicators, Gekkonidae, Reptile, Trace Elements, Urban Pollution

SREL Reprint #3097

Fletcher, D. E., W. A. Hopkins, M. M. Standora, C. Arribas, J. A. Baionno-Parikh, T. Saldaña, and C. Fernández-Delgado. 2008. Geckos as Indicators of Urban Pollution. In: J. C. Mitchell, R. E. Jung Brown, and B. Bartholomew (Eds.). Urban Herpetology. Society for the Study of Amphibians and Reptiles. Herpetological Conservation Number 3: 225-237.