Wall lizards

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Wall lizards

 

The common wall lizard, Podarcis muralis, is a small, diurnal, lizards that is wide spread throughout southern Europe. It is aptly named, because it is often very abundant – in particular on dry stone walls – and this makes it easy to find and catch. It is also very easy to keep and breed in captivity. So if there would be anything interesting about its biology, it would make for a great study species.

In fact there are several features that make it interesting to us. These include having a broad geographic and climatic distribution from sea level to high altitude with many island populations and isolated populations at range margins, extensive genetic and phenotypic divergence between regions, hybrid zones between phenotypically distinct lineages, within-population polymorphism and interesting reproductive biology.

Our interest was initially drawn to wall lizards because they are introduced into many places where the species is not native, including tens of populations in England. Studying non-native species allow us to study evolutionary processes as they happen. For example, animals introduced from Tuscany or southern France to England will encounter a very different climate to what they are used to (reflect on the choice between holidays in the Riviera or the ‘English Riviera’). But wall lizards have coped with, and even adapted to, their new environments. For example, non-native lizards lay eggs with more advanced embryos that develop faster at cooler temperatures than native lizards.

BBC visited our lab in 2014 to film a clip about these Mediterranean migrants in the UK, which aired on the One Show:

 

Our research on wall lizards is a collaborative effort that involves teams from several countries, including Italy, France, Germany, Portugal, Spain and Australia. This helps us to build large data sets, assist each other with particular methods, and help out with logistics during field work. It is an excellent research environment for those who wish to develop their own project ideas and make use of wall lizards to answer outstanding problems in evolutionary biology.