The Leaf-Toed Gecko (Euleptes europaea) is an endemic species of the Mediterranean, with a distribution that spans several islands: Sardinia and the Tuscan Archipelago in Italy, Corsica and the islands off the Provençal coast in France, and the Galite Archipelago in Tunisia. Its low biomass and ability to thrive in very small populations make this species particularly well-suited to island life. However, the species is currently declining, particularly at the edge of its range.

This small, nocturnal, and elusive species is difficult to monitor. To study such reclusive reptiles, artificial retreat sites (ARS) are often used to restore habitats and facilitate research. Between 2014 and 2016, ARS were installed on the islands of Gran Rouveau and If in France to monitor Leaf-Toed Gecko populations. A recent study, published in Acta Herpetologica, evaluated the individual and environmental factors influencing the use of ARS by this species, with the aim of better understanding the gecko's ecological preferences.

In spring 2021 and 2022, environmental data were collected on Gran Rouveau and If Islands, and occurrence data were retrieved from samplings conducted between 2014 and 2022. The geckos showed a preference for ARS that were moderately exposed to wind and sunlight and surrounded by bushy vegetation. Interestingly, the geckos do not thermoregulate through direct exposure to sunlight; instead, the positioning of their retreat sites enables them to maintain an optimal body temperature. Accordingly, the presence of the geckos in ARS was negatively correlated with the air temperature of the previous night, suggesting that they rely on their retreat sites for thermal stability, especially when temperatures are lower.

ARS presence was also correlated with the presence of geckos on the previous day, indicating a certain degree of site fidelity. This was further supported by the observed lack of movement from one retreat site to another. However, human disturbance, such as the dismantling and rebuilding of ARS or the manipulation of geckos for tag implantation, negatively impacted ARS presence on subsequent days. Such a disturbance likely pushed the geckos toward nearby, undisturbed natural retreat sites.

While some aspects of ARS selection and use still require further study to overcome existing limitations, the findings of this research are valuable for improving population monitoring and informing effective conservation strategies.

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