Distribution

An indigenous population of the common wall lizard is present only in the southern city of Maastricht, where it reaches its northern distribution limit. The common wall lizard is distributed along old city walls, railway embankments, industrial areas and the banks of the river Meuse.

Status

The common wall lizard is listed on the Red List as critically endangered. It is strictly protected under Dutch legislation, the Bern Convention (Annex ii) and the Habitats Directive (Annex iv). The common wall lizard is present in less than 1% of the Dutch 5×5 km grid cells. Within the city of Maastricht 77% of the known locations have disappeared during the last century. The decrease is caused by the demolition of most old city walls and fortifications, a lack of management and large scale renovations of the remaining walls. Around 1980 the total Netherlands populations consisted of less than 100 animals. Around 1990 the indigenous population had grown to some 140 animals. In 2004 the population size was estimated to be around 900 due to good habitat management, favourable weather conditions and a higher research intensity. Numbers have declined slightly since then, but new locations have been colonised. The situation is much more favourable than in the 1970s and 1980s. The species is helped by using special techniques when restoring old walls and by a well thought-out management of the vegetation by extensive sheep grazing and mowing. The special way of consolidating old walls together with the vegetation management proved to be very successful.

Remarks

Common wall lizards in Maastricht differ from those in nearby Belgian and German populations by their belly colour. Practically all Maastricht males have red bellies. During the long period that this population has been studied, very few males with white or yellow bellies have been found; colours that are common in neighbouring foreign populations. This might be the consequence of long term isolation. Maastricht animals are slightly smaller than animals in neighbouring countries.

There are several introduced populations of common wall lizards in the Netherlands. The introduced animals originate from different central and southern European countries. Even some 220 km north of Maastricht a large breeding group of introduced animals is present.

Bron

Auteur(s)

Tilmans, R.A.M. , Frissen-Moors, C.M.M.

Publicatie

• Creemers, R.C.M. & J.J.C.W. van Delft 2009. De amfibieën en reptielen van Nederland. Nederlandse Fauna 9. Nationaal Natuurhistorisch Museum Naturalis, KNNV Uitgeverij & European Invertebrate Survey-Nederland, Leiden.