Reptiles are unable to generate metabolic heat and regulate body temperature behaviorally depending on environmental conditions. The thermal quality of their habitat is therefore of pivotal importance for their survival. Lizards render themselves as ideal ectothermic models, and their thermal biology has been extensively studied. In this work, we focused on the thermoregulatory performance of the endemic Milos wall lizard (Podarcis milensis) (Milos Archipelago, Aegean Sea, Greece). Applying the same standard methodology, we estimated the effectiveness of thermoregulation (E) taking into account the three main thermal parameters: body (T_b, the temperature of active animals in the field), environmental (T_e, the temperature that animals would achieve in the field if passively conform to the environment) and preferred temperatures (T_pref, the temperatures an animal achieves in a laboratory thermal gradient). Here, we compare the thermoregulatory profile of two remote rocky islet populations, Falconera and Velopoula, with the Milos Island population. We collected T_b values from active lizards as well as T_e from specially designed copper models, which were appropriately placed in the field so as to cover all possible microhabitats. Lizards were then transported to the laboratory where we assessed their T_prefs. Falconera and Velopoula populations showed the same high thermoregulatory effectiveness as that of Milos Island (E_Falconera = 0.97, E_Velopoula = 0.95, E_Milos = 0.89). However, when we used an alternative evaluation of the thermoregulatory strategy, the E values outlined a much more effective thermoregulation for the islets: de-db_Falconera = 6.97, de-db_Velopoula = 11.54, de-db_Milos = 4.27. The adverse conditions on the islets outline a demanding habitat of low thermal quality that dictates effective thermoregulation. However, the trend of increasing temperatures depicts an even harsher environment for the years to come. Could lizards that have already achieved the highest thermoregulatory effectiveness and cannot escape from the isolated islets they dwell cope with these new conditions? This is the kind of questions to which conservation biology will be called upon to respond.

Tissue regeneration is a fundamental evolutionary adaptation, which is well known in lizards that can regenerate their entire tail. However, numerous parameters of this process remain poorly understood. Lizard tail serves many functions. Thus, tail autotomy comes with many disadvantages and the need for quick regeneration is imperative. To provide the required energy and materials for caudal tissue building, lizards are expected to undergo a number of physiological and biochemical adjustments. Previous research showed that tail regeneration induces changes in the digestive process. Here, we investigated if and how tail regeneration affects the digestive performance in five wall lizard species deriving from mainland and island sites and questioned whether the association of tail regeneration and digestion is affected by species relationships or environmental features, including predation pressure. We expected that lizards from high predation environments would regenerate their tail faster and modify accordingly their digestive efficiency, prioritizing the digestion of proteins; the main building blocks for tissue repair. Second, we anticipated that the general food shortage on islands would inhibit the process. Our findings showed that all species shifted their digestive efficiency, as predicted. Elongation rate was higher in sites with stronger predation regime and this was also applied to the rate with which protein digestion raised. Gut passage time increases during regeneration so as to improve the nutrient absorbance, but among the islanders, the pace was more intense. The deviations between species should be attributed to the different ecological conditions prevailing on islands rather than to their phylogenetic relationships.

Caudal autotomy is a well-known and widely used defensive strategy among lizards, but its impact on social behaviour, particularly in intramale interactions and dominance hierarchies, has been relatively understudied. In this study, we examined the effects of tail autotomy and subsequent regeneration on the social hierarchy of male Aegean wall lizards (Podarcis erhardii), a territorial species of lacertid lizards. We found that tail loss significantly reduced the ability of adult males to dominate same-sized conspecifics, hinting at a possible difficulty in securing high-quality territories, potentially reducing access to mating opportunities and increasing mortality risks. Both autotomised dominant and intact subordinate males in our interactions adjusted their behaviour following autotomy, with dominant males reducing their aggression and subordinate ones increasing theirs. Surprisingly, tail regeneration did not restore social status or aggression levels to pre-autotomy conditions, suggesting that social costs of tail loss could extend beyond the associated decrease in body size and may persist even after the tail has fully regenerated. These results indicate that caudal autotomy could have lasting consequences on male social interactions and potentially significant implications for reproductive success and survival. Our study highlights the complex role of tail condition in the social dynamics of territorial lizards and calls for further research on the long-term impacts of autotomy on fitness and social structures.