Mediterranean expats – populations of Kotschyi’s gecko thriving at the edge of the Pannonian plain in Serbia

Abstract

Human activities, especially transportation and urbanization, coupled with climate change, can lead to changes in faunal compositions of some regions through range shrinking/expansion of certain species. Some lizards, particularly geckos, proved as adept colonizers, especially in urban ecosystems. The Kotschyi’s gecko (Mediodactylus kotschyi sensu lato) is a small crepuscular and nocturnal lizard characteristic for the eastern Mediterranean. Recent molecular analyses showed that it is, in fact, a species complex. In Serbia, Kotschyi’s gecko naturally occurs only in Prizren, Metohia, but recently it reached the southern edges of the Pannonian plain, which are under the strong influence of continental climate (hot summers and cold winters, with long periods of frost). Recently several populations of this small, inconspicuous lizard were discovered in Novi Sad, Belgrade, Smederevo and Pančevo, and possibly Niš, further to the south. The hypothesis of introduction during historic times was proposed, but a more likely explanation is a relatively recent simultaneous introduction, probably facilitated through railroad beds as corridors. Taxonomic identity of the introduced populations is still poorly known, but according to their morphological characters, they most likely belong to the kotschyi group. Involvement of citizen scientists, who shared their gecko findings with the Serbian Herpetological Society, proved invaluable in detecting the cases of introduction of this lizard. Such cooperation will further be encouraged and facilitated.