As the winter approaches reptiles are preparing for brumation, a process similar to hibernation but for cold-blooded animals, to handle an extreme change in temperature, burying themselves under the soil. Reptiles are crucial to study due to their high susceptibility to environmental changes and our projects focus on the habitat preference of the Common chameleon (Chamaeleo chamaeleon; Figure 1) and population estimation of the fresh water Balkan terrapin (Mauremys rivulata) and European Pond terrapin (Emys orbicularis).

Figure 1 – C. chamaeleon hatchling. Samos island, Greece.

The common chameleon is an important reptile species found in a few locations in Europe. One of those is on the Greek island of Samos. The IUCN Red List of Threatened Species classifies it as “least concern”, but because the population is restricted to the island of Samos, more conservation measures have to be implemented. Studies on chameleon habitat are necessary to understand their adaptation to the environmental changes. Surveys are carried out in different habitats such as forests, riverbeds (Figure 2), salt marshes, olive groves, and coasts, where chameleon presence, environmental data and vegetation type are recorded.

Figure 2 – Riverbed habitat. Samos island, Greece.

Currently the areas with the highest abundance of chameleons are riverbeds near the coast (55%). This could be for many reasons; ease of access to fresh water, a suitable habitat to lay eggs or a safe place to prepare for the winter. Chameleon populations are constantly under pressure on the island due to fires, domestic animals, roadkills, insecticides, and many other anthropogenic factors. Hopefully, these studies will push for conservation acts to protect the common chameleon.

Terrapins are another important reptile species found on the island of Samos in select water sources. These water sources usually run out into the sea providing suitable habitats for both freshwater and saltwater species. The study site for terrapins is a mill ruin located in Mesokampos (Figure 3) that supports many forms of other wildlife such as birds, plants, eels, and fish.

Figure 3 – Mesokampos Mill Field Site. Samos island, Greece.

The purpose of this study is to determine the populations of two terrapin species within the mill, E. orbicularis (Figure 4) and M. rivulata; (Figure 5)

Figure 5 – M. rivulata. Samos island, Greece.
Figure 4 – E. orbicularis. Samos island, Greece






To determine population, terrapins are captured and marked along the shell to identify individuals for recapture. Measurements are also collected to study growth rates in the future. So far, 24 Balkan terrapins and 13 European pond terrapins have been marked.

Reptiles play a crucial role in the ecosystem on the island of Samos because they are extremely sensitive to their environment. Studies on reptiles can greatly aid in the conservation and restoration of the ecosystem of the entire island of Samos.

Jason Nagro, Environmental Science

University of Oregon, USA