Aspects of thermal ecology of the meadow lizard (Darevskia praticola)

Abstract

We studied the thermal biology of the meadow lizard (Darevskia praticola) in the peripheral part of its distribution range (westernmost edge of the distribution area). We assessed whether these lizards actively thermoregulate, estimated the accuracy and effectiveness of thermoregulation, and evaluated the thermal quality of the habitat using the standard thermal parameters: body (Tb), preferred (Tpref) with set-point range (Tset) and operative temperatures (Te). Tset of the meadow lizard under controlled laboratory conditions was between 27.8°C and 31.4°C. In the field Tb and Te averaged 29.0°C and 26.1°C, respectively. A large proportion of Tes fell below the Tset range of the meadow lizard, and lizard Tbs were substantially closer to the species’ Tset range. Obtained values of thermoregulatory indices suggested that the meadow lizard thermoregulated actively, with a rather high accuracy (d¯b=0.8) and effectiveness (E=0.8 and d¯e−d¯b=2.6), and that their habitat at this locality was thermally favourable during the spring. Our results suggest that thermal requirements of the meadow lizard resemble those of alpine lacertids, while their Tbs and Tset are lower than in most lacertid lizards. Further thermoregulation studies could be an important step in predicting the impact of the global climate change on the meadow lizard and the risks of local extinctions of its peripheral populations.