Some like it hotter: Differential thermal preferences among lizard color morphs

Asher Thompson; Vassiliki Kapsanaki; Heather E M Liwanag; Panayiotis Pafilis; Ian J Wang; Kinsey M Brock

doi:10.1016/j.jtherbio.2023.103532

Some like it hotter: Differential thermal preferences among lizard color morphs

J Therm Biol. 2023 Apr:113:103532. doi: 10.1016/j.jtherbio.2023.103532. Epub 2023 Mar 1.

Authors

Asher Thompson¹, Vassiliki Kapsanaki², Heather E M Liwanag³, Panayiotis Pafilis⁴, Ian J Wang⁵, Kinsey M Brock⁶

Affiliations

¹ Department of Environmental Science, Policy, and Management, College of Natural Resources, University of California, Berkeley, CA, USA.
² Department of Biology, National and Kapodistrian University of Athens, Athens, Greece.
³ Department of Biological Sciences, California Polytechnic State University, San Luis Obispo, CA, USA.
⁴ Department of Biology, National and Kapodistrian University of Athens, Athens, Greece; Zoological Museum, National and Kapodistrian University of Athens, Athens, Greece.
⁵ Department of Environmental Science, Policy, and Management, College of Natural Resources, University of California, Berkeley, CA, USA; Museum of Vertebrate Zoology, University of California Berkeley, Berkeley, CA, USA.
⁶ Department of Environmental Science, Policy, and Management, College of Natural Resources, University of California, Berkeley, CA, USA; Department of Biology, National and Kapodistrian University of Athens, Athens, Greece; Museum of Vertebrate Zoology, University of California Berkeley, Berkeley, CA, USA. Electronic address: kbrock@berkeley.edu.

PMID: 37055135
DOI: 10.1016/j.jtherbio.2023.103532

Abstract

Temperature rules the lives of ectotherms. To perform basic biological functions, ectotherms must make behavioral adjustments to keep their body temperatures near a preferred temperature (Tpref). Many color polymorphic lizards are active thermoregulators and exhibit morph differences in traits related to thermoregulation, such as color, body size, and microhabitat use. The Aegean wall lizard, Podarcis erhardii, is a heliothermic lizard with orange, white, and yellow color morphs that differ in size, behavior, and microhabitat use. Here, we tested whether P. erhardii color morphs from the same population from Naxos island, Greece, differ in Tpref. We hypothesized that orange morphs would prefer lower temperatures than white and yellow morphs because orange morphs are often found on cooler substrates and in microhabitats with more vegetation cover. We obtained Tpref for 95 individuals using laboratory thermal gradient experiments of wild-caught lizards and found that orange morphs do, indeed, prefer cooler temperatures. Average orange morph Tpref was 2.85 °C lower than average white and yellow morph Tpref. Our results add support to the idea that P. erhardii color morphs have multivariate alternative phenotypes and present the possibility that thermally heterogeneous environments play a role in the maintenance of color polymorphism in this species.

Keywords: Aegean wall lizard; Alternative phenotypes; Podarcis erhardii; Polymorphism; Preferred temperature; Thermoregulation.

MeSH terms

Animals
Body Temperature Regulation
Color
Female
Greece
Hot Temperature
Lizards* / physiology
Male