Podarcis pityusensis – Eisentraut’s finches

Martin Eisentraut was a German zoologist and he shuffled these lizards from island to island almost hundred years ago. He wanted to learn from different developments of separated populations. The Ibiza Wall Lizard is very variable, the same species comes in different color forms. Knowing that, we must say the shown lizards are the more plain variation, there are darker, blue-bellied populations as well! Blue animals always look amazing! This evolutionary effect is called melanism, they have more dark pigments, like a panther. It can have benefits of better camouflage and thermoregulation (link to a study about melanism in crickets). On Ibiza we didn’t see any blue specimens.

So what did Eisentraut learn? Here’s a paper (Pérez-Mellado et al., 2017) talking about that. The issue: He identified five lizard-free islands, so that he can control which kind of variation starts the new population. But unfortunately, it looks like he overlooked some lizards on one island. On two other islands no more lizards were found in 2017, what could mean that these places were just not suitable for them. Anyways in the study from 2017 one new population was discovered! And we learned that one species can change a lot in order to adjust to the environment – and that is how evolution works! I’m not sure what Eisentraut took away from his experiments.

The Ibiza Wall Lizard can be found almost everywhere on Ibiza. They are a bit shy, but when you wait a moment, taking pictures from 1-2m distance is possible. Fun fact, one day we discovered a small beach where a group of lizards captured our towel while we were resting on it and even climbed on our arms. Believe it or not, we didn’t have the camera ready and cannot prove it.