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Body surfaces of reptiles as projection screens of evolution
Abramjan, Andran ; Frynta, Daniel (advisor) ; Rehák, Ivan (referee) ; Šulc, Michal (referee)
The PhD thesis deals mainly with the coloration (and also scalation) of selected reptile species and explores evolutionary or ecological contexts indicated by these traits. The main topics can be roughly divided into two groups: 'antipredation signals' and 'effects of parthenogenesis'. The dominant method used in most studies is visual modelling. The work consists of the following case studies. 1) Blue-tongue skinks use their conspicuous blue tongues to threaten potential predators. We found that the tongue has a relatively high UV reflectance, a typical feature of intraspecific communication in lizards. Using visual models, we investigated how the blue tongue is perceived by the conspecifics and predators (birds of prey). In both visual models, the UV-blue tongue appears more conspicuous against the natural background than a pink tongue. In addition, in the conspecifics model, its hue partially overlaps with hues of UV-blue spots, which are sexually selected traits in various species of lizards. Thus, the UV-blue tongue seems to contribute to the effectiveness of the deimatic display and its possible role in intraspecific communication cannot be ruled out either. 2) We detected UV reflectance in non-pigmented areas of the skin in the Leopard gecko (Eublepharis macularius). These form white patches...
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Body surfaces of reptiles as projection screens of evolution
Abramjan, Andran ; Frynta, Daniel (advisor) ; Rehák, Ivan (referee) ; Šulc, Michal (referee)
The PhD thesis deals mainly with the coloration (and also scalation) of selected reptile species and explores evolutionary or ecological contexts indicated by these traits. The main topics can be roughly divided into two groups: 'antipredation signals' and 'effects of parthenogenesis'. The dominant method used in most studies is visual modelling. The work consists of the following case studies. 1) Blue-tongue skinks use their conspicuous blue tongues to threaten potential predators. We found that the tongue has a relatively high UV reflectance, a typical feature of intraspecific communication in lizards. Using visual models, we investigated how the blue tongue is perceived by the conspecifics and predators (birds of prey). In both visual models, the UV-blue tongue appears more conspicuous against the natural background than a pink tongue. In addition, in the conspecifics model, its hue partially overlaps with hues of UV-blue spots, which are sexually selected traits in various species of lizards. Thus, the UV-blue tongue seems to contribute to the effectiveness of the deimatic display and its possible role in intraspecific communication cannot be ruled out either. 2) We detected UV reflectance in non-pigmented areas of the skin in the Leopard gecko (Eublepharis macularius). These form white patches...
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