Broad seasonal changes in thermoregulation of Podarcis lilfordi (Squamata, Lacertidae) at Binicodrell islet (Menorca, Spain)

Abstract

Most lizards maintain quite constant body temperatures by behavioural means. Seasonal variations of environmental factors, such as temperature, sunlight exposure and wind intensity, influence lizard thermoregulatory abilities. Understanding how seasonal environmental shifts influence lizards’ thermoregulation helps us to know how they deal behaviourally with environmental changes, in general. We examined seasonal shifts (spring vs. summer) in behavioural thermoregulation in Podarcislilfordi from Binicodrell islet (Menorca, Spain). Operative temperatures varied between microhabitats and seasons, being lower in spring than in summer, regardless of sunlight exposure. Lizard body temperatures were also lower in spring than in summer. Lizards used sunny microhabitats more frequently in spring and shaded areas in summer. Habitat thermal quality was similar during both seasons, but lizards thermoregulated less accurately in spring than in summer. Thermoregulatory effectiveness was low in spring (0.28) and moderate in summer (0.76). In comparison with previously published results, our findings showed the marked seasonal variation in the effectiveness of thermoregulation amongst island populations, which should be considered in future comparative studies.

Seasonal Variation in the Thermoregulation Pattern of an Insular Agamid Lizard

“…On the other hand, not all islands are characterized by equally favorable climates due to their discrete morphological attributes such as size, wind exposure, and geographic location [62]. Therefore, lizards inhabiting minuscule islets have to demonstrate exceptional thermoregulation efficiency to ensure their survival [15,[26][27][28]. According to our results, this is also the case for L. stellio inhabiting the largest of the Cyclades, Naxos Island.…”

“…Seasonal variations in environmental conditions, such as rainfall, wind intensity, temperature, and sunlight exposure may influence many of the behavioral and physiological attributes of lizards [13,14], including thermoregulation [15,16]. For example, subtropical lizards may shift their activity and thermoregulation effort as a response to weather fluctuations but are sensitive to extreme winter conditions [17].…”

“…To avoid islet particularities, we focused on a population inhabiting the largest Cycladic Island, Naxos (430 km 2 ). Just a handful of studies have assessed the effect of thermoregulatory seasonality on Mediterranean lizards [15,18,29,30] and none has focused on a large island.…”

Multi-Site and Multi-Year Remote Records of Operative Temperatures with Biomimetic Loggers Reveal Spatio-Temporal Variability in Mountain Lizard Activity and Persistence Proxy Estimates

“…Thus, a low elevation habitat may be more favorable than a high elevation habitat. All these results partially challenge the hypothesis that species would migrate to higher altitudes with more favorable temperatures [58,69] and highlight the role of slope orientation and habitat on the micro-climate felt by individuals [62,115,116].…”