Erhard's wall lizard (or Aegean wall lizard, Podarcis erhardii) is the most common lizard of Alonissos, as well as of all lowland and semi-mountainous Greece. The hiker will likely see it very often, in all the habitats of the island, from the phrygana to the ruins.

It is a very slender lizard, active throughout the day, even in the warm periods of Winter. It feeds on invertebrates.
Many subspecies have been recognized in insular Greece, due to the long isolation of the islands. In Alonissos (as well as in Kyra Panagia and Gioura) the subspecies ruthveni has been recorded.

A detailed description of the Main road-Steni Vala trail, along with interactive maps, photos and POIs, is included in the digital field guide Alonnisos topoguide.

The digital field guide Alonnisos topoguide is available for Android devices as an in-app purchase within the application topoguide Greece. Alonnisos topoguide is a member of the Greek Islands group.

The digital field guide Alonnisos topoguide is also available for iOS (iPhone and iPad) devices as an in-app purchase within the application Topoguide Greece. There also, Alonnisos topoguide is a member of the Greek Islands group.