The wall lizard has been expanding rapidly – why that’s not necessarily a good thing

The sun is shining, there is a rustle, a lizard rushes by and crawls into a crevice. Scenes that many associate with holidays in Ticino or Valais. But the animals are appearing more and more often north of the Alps – especially in the cities. Andreas Meyer from the Coordination Center for the Protection of Amphibians and Reptiles in Switzerland explains why this is not all good news.

The impression is not misleading, but Meyer explains: “You have to differentiate a bit. We have four species of lizards in Switzerland. The population of three species is declining, only the population of the wall lizard is increasing sharply.

To illustrate this, the reptile expert shows two distribution maps. One from 1990, the other from 2021. You can see the triumph of the wall lizard:

As already mentioned, in Switzerland there are four relevant species of lizards. According to the Reptile Advice Center (Karch), these are:

By the way: more information about the lizard species in Switzerland can be found on the Karch website.

On the one hand, 30 years ago it was still too cold in the north for the wall lizard. Due to global warming, she now feels more and more comfortable in more northern regions.

Meyer gives more reasons for the rapid increase: “Wall lizards are extremely adaptable and get along well with each other, even in urban habitats.”

Because wall lizards like to climb onto train carriages, they often travel as stowaways throughout Switzerland. “They are often transported from place to place, for example by all kinds of freight transport, or in the form of eggs in the pots of ornamental and useful plants.”

Moreover, they are more competitive than the sand lizard: “The wall lizard gets along better with domestic cats than the other species. This is partly because she climbs well and is very agile.”

“In principle it’s not bad,” says Meyer. “But that should not obscure the fact that other types of lizards are doing less well.”

Less good resources: sand lizards and green lizards are considered endangered species in Switzerland, and the forest lizard as potentially endangered. Only the wall lizards are not considered endangered.

The effects of the growing population on local flora and fauna have not yet been studied in detail. “But it is worrying that the wall lizard is competing with the sand lizard,” says Meyer. “We have to assume that in some places the sand lizard will be displaced by the wall lizard.”

Among pets, domestic cats in particular pose a danger to all types of lizards. The problem here is that there are hardly any options to do anything for the reptiles. “Glöggli does not work on reptiles.”

But: “You can improve the shelters in the garden, which can increase the lizards’ chances of survival.” It would also help to not let the cat out of the house at all or less, “but that is not always possible and not in the cat’s interest,” Meyer emphasizes.

The scientist adds: “But what you should think about if you care about local nature: do you really want a cat, or can you do without it?”

Meyer explains: “In the tails of lizards, there are predetermined breaking points between the vertebrae where the tail can be thrown off under tension. At this time, a muscle contraction closes the blood vessels so that the animal does not bleed to death. Within a few months, a regenerated tail grows back from this wound, almost as long as the original tail. But the scales are slightly different and you can see that the lizard no longer has its original tail.”