Allozyme Evidence for Insularity in Exotic Populations of the Mediterranean Gecko (Hemidactylus turcicus)

Abstract

Man's ability to travel and transport materials vast distances in recent years has dramatically increased the introduction of exotic species into the biota of other countries. In spite of the fact that these introductions can lead to the displacement or extinction of native animals (e.g., Petren et al., 1993), few studies of introduced fauna exist (Atkinson, 1989). One of these introduced species, the Mediterranean gecko (Hemidactylus turcicus), is a nocturnal, insectivorous lizard, naturally found on rocky cliffs in countries bordering the Mediterranean Sea and in other areas of the Middle East (Arnold et al., 1978). The gecko has been introduced into the southern United States (e.g., see Rose and Barbour, 1968; Selcer, 1986) and is now found on the external walls of buildings in several port cities, including Mobile and Fairhope, Alabama (Mount, 1975; Dundee, 1984). Nelson and Carey (1993) believe that H. turcicus was introduced via ships and transported by truck or rail from these original sites to new localities. Importantly, they suggest that individual geckos (at least in the areas they surveyed) do not naturally disperse between buildings and thus form discrete populations. To confirm this behavior we studied the genetics of individuals from several buildings, separated by different distances.