The interesting case of the Wall Lizard

A female (I assume) Wall Lizard, Podarcis muralis, on - surprise, surprise - a wall.

I visited Ault Park in Cincinnati on October 21, mostly to see the small colony of Cassius Blue butterflies that appeared there. No problem finding the butterflies, which I am sure did not get there under their own power. I'll hopefully write more about that situation later.

As it turns out, Ault Park hosts a sizeable population of Wall Lizards. It was not hard to find them, in fact, one cannot help but see them if the temperatures are warm enough. Add some sun, and they'll come out in droves and bask on exposed surfaces.

A Wall Lizard peeks from cover. These lizards are astonishingly fast when they need be, and if disturbed shoot under cover. They are almost always around rocks, cement steps and ledges, walls or other structures offering niches into which they can tuck themselves.

Here's a male showing extraordinary colors and patterning. I made this shot in 2011, also in Cincinnati. That was the last time that I had been around these lizards prior to this experience.

Wall Lizards range widely throughout Europe, ranging all the way to Turkey. The lizard is decidedly NOT native here in Ohio. In 1951, a boy named George Rau,  stepson of Fred Lazarus III the department store magnate, released about ten lizards at the Lazarus's family home in Cincinnati. George caught the lizards near Milan, Italy and apparently smuggled them back to the states.

The climate in the Milan region is only marginally warmer than southern Ohio, and the Wall Lizards flourished. They have spread throughout much of the Greater Cincinnati area and somewhat beyond. Densities as high as 1,500 animals an acre have been reported in optimal habitat.

Lizards have managed to get to adjacent areas in Indiana and Kentucky. In 2020, animals were found near Dayton, and in Delaware (Ohio). It will be interesting to see if these lizards are the nucleus of a coming invasion. Wall Lizards have long been established on Vancouver Island, British Columbia, and have occasionally turned up in points south along the west coast.

A big question would be: Do nonnative Wall Lizards wreak ecological havoc by displacing native lizards, and annihilating beneficial native insects and other invertebrates? I've not heard a good answer to that, at least regarding lizards in the Cincinnati area. From my limited experience, the Wall Lizards are often in very urban and unnatural environments - places that it would seem unlikely that native skinks or the Fence Lizard would flourish. The Wall Lizard's strong fidelity to rocky places - or utterly artificial analogs - greatly limit where it can live. Indeed, its scientific epithet muralis means "of walls". A botanical counterpart of the lizard is the Kenilworth Ivy, Cymbalaria muralis, which is indigenous to the same general area as the lizard. It too made its way to North America, but remains confined to rocky places and artificial walls. But maybe I'm all wet on the lizard's impacts, and they do cause damage that I'm unaware of.  

In any event, it is interesting to see scads of lizards racing about in places that you wouldn't expect them. And the story of their introduction illustrates how nonnative species can be introduced, and gain a major foothold.