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Identifying population changes is a prerequisite for any conservation efforts, but to evaluate trends requires long-term data sets. In this paper, changes in population numbers in two species of European lizards, Lacerta bilineata and Podarcis muralis, are described. The results are based on counts of mortalities and live lizard presence on roads collected over a 14 year period, which indicated wide annual fluctuations in numbers in both species, with inter-specific annual trends strongly correlated. Snout to vent lengths (SVL) in L. bilineata were generally longer when annual numbers were higher but not in P. muralis. Regression analysis of the logarithmic transforms of annual lizard numbers as dependent variables and year as the independent variable indicated that despite population fluctuations, numbers of both species were stable or increased during the period of observation. Jackknife analysis identified unusually high numbers of L. bilineata in 2012 and P. muralis in 2010, but data from these years had minimal influence on the general trends with the peudo-regression coefficients generated from the Jackknife analysis in agreement with the true regressions. The results were therefore congruent, indicating annual fluctuations in both species were underpinned by long-term population stability.

Abstract. The rapid expansion of urban environments invariably presents a novel series of pressures on wildlife due to changes in external environmental factors. In reptiles, any such changes in temperature are critical since thermoregulation is the key driver in the function of many physiological processes. How reptiles adapt to such changes may vary from those species that are impacted negatively to others that have the behavioural flexibility to exploit new conditions. In this paper we describe retreat site selection, movements and aspects of the thermal ecology of the African lizard Agama agama in urban environments of West Africa. In early evening lizards began movement from late-afternoon core activity areas and ascended the walls of houses for overnight retreats. A high proportion retreated to locations in groups under or on top of warm electrical panels. The thermal potential these panels offered was the attainment of body temperatures equal to or higher than the minimum preferred body temperature (PBT ≈ 36 ∘C in A. agama) and hence increased physiological performance. The lizards that took advantage of the heat sources travelled further each day to and from diurnal activity areas than individuals that spent the night high on walls but not next to heat panels. There were both potential costs (enhanced predation pressures) and benefits (impacts on thermal ecology, retreat site selection) of this behaviour for lizards living in urban environments.

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Observations have been made during both cloudy and sunny weather on the body temperatures of the glass lizard Ophisaurus apodus in Yugoslavia. The results indicate that during sunny weather this species is heliothermic elevating its body temperature to around 30°c. When the weather was cloudy glass lizards were observed abroad on grass covered clearings but body temperatures were significantly lower during cloudy weather than those recorded under sunny weather. There was no significant difference between body temperatures measured during sunny weather in May and sunny weather in September and October. The body temperatures of males, females and juveniles were not significantly different during sunny or cloudy weather. For most of the daily period there was little difference between body temperatures except between 1700-1900 hrs when they were significantly lower. In general, the body temperatures of field measured 0. opodus were lower than those recorded from animals in laboratory heat gradients (Cherchi, 1961; Hailey, 1984).