A comparative study of two agamid lizards,Laudakia stellioandPseudotrapelus sinaitus , in southern Sinai

Egyptian Journal of Biology

O Norfolk¹  F Gilbert¹  S Zalat¹  T Reader¹  A Melotte¹ 

关键词: thermoregulation;    colour change;    social signalling;   

DOI  :  

学科分类：生物科学（综合）

来源: Egyptian-English Society for Biological Sciences

【 摘 要 】

The study compared habitat use and behaviour in two sympatric species of agamid lizard, Laudakia stellio and Pseudotrapelus sinaitus. Despite sharing the same habitat, the two species differed in their utilisation of microhabitats within it. Pseudotrapelus spent significantly longer on rocks compared to Laudakia. Pseudotrapelus showed evidence of heliothermic regulation, spending most of the time in the sun, but moving into the shade in the warmer afternoons. These varying temporal patterns may reflect differential thermoregulatory requirements between the two lizard species. Pseudotrapelus can change colour rapidly. There was no evidence of any thermoregulatory function in this ability; it is likely to be a form of social communication. Being brightly coloured was associated with behaviours implying increased conspicuousness: blue lizards were alert and vigilant for an average of 93% of each viewing session, compared to just 60% of the time in non-blue camouflaged lizards. The striking nature of the transitory blue colouration suggests it may have evolved for maximum salience, a trait common with signals. We simulated social encounters using blue model lizards and mirrors. Behavioural responses to these stimuli all involved colour changes, and support the social-signaling hypothesis.

【 授权许可】

Unknown