Abstract
Bright coloration and complex visual displays are frequent and well described in many lizard families. Reflectance spectrometry which extends into the ultraviolet (UV) allows measurement of such coloration independent of our visual system. We examined the role of colour in signalling and mate choice in the agamid lizard Ctenophorus ornatus. We found that throat reflectance strongly contrasted against the granite background of the lizards' habitat. The throat may act as a signal via the head-bobbing and push-up displays of C. ornatus. Dorsal coloration provided camouflage against the granite background, particularly in females. C. ornatus was sexually dichromatic for all traits examined including throat UV reflectance which is beyond human visual perception. Female throats were highly variable in spectral reflectance and males preferred females with higher throat chroma between 370 and 400 nm. However, female throat UV chroma is strongly correlated to both throat brightness and chest UV chroma and males may choose females on a combination of these colour variables. There was no evidence that female throat or chest coloration was an indicator of female quality. However, female brightness significantly predicted a female's laying date and, thus, may signal receptivity. One function of visual display in this species appears to be intersexual signalling, resulting in male choice of females.
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Selected References
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- Beazley L. D., Sheard P. W., Tennant M., Starac D., Dunlop S. A. Optic nerve regenerates but does not restore topographic projections in the lizard Ctenophorus ornatus. J Comp Neurol. 1997 Jan 6;377(1):105–120. doi: 10.1002/(sici)1096-9861(19970106)377:1<105::aid-cne10>3.0.co;2-p. [DOI] [PubMed] [Google Scholar]
- Bennett A. T., Cuthill I. C., Partridge J. C., Lunau K. Ultraviolet plumage colors predict mate preferences in starlings. Proc Natl Acad Sci U S A. 1997 Aug 5;94(16):8618–8621. doi: 10.1073/pnas.94.16.8618. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ellingson J. M., Fleishman L. J., Loew E. R. Visual pigments and spectral sensitivity of the diurnal gecko Gonatodes albogularis. J Comp Physiol A. 1995 Nov;177(5):559–567. doi: 10.1007/BF00207185. [DOI] [PubMed] [Google Scholar]
- Leal M. Honest signalling during prey-predator interactions in the lizard Anolis cristatellus. Anim Behav. 1999 Sep;58(3):521–526. doi: 10.1006/anbe.1999.1181. [DOI] [PubMed] [Google Scholar]
- Loew E. R. A third, ultraviolet-sensitive, visual pigment in the Tokay gecko (Gekko gekko). Vision Res. 1994 Jun;34(11):1427–1431. doi: 10.1016/0042-6989(94)90143-0. [DOI] [PubMed] [Google Scholar]
- Loew E. R., Govardovskii V. I., Röhlich P., Szél A. Microspectrophotometric and immunocytochemical identification of ultraviolet photoreceptors in geckos. Vis Neurosci. 1996 Mar-Apr;13(2):247–256. doi: 10.1017/s0952523800007483. [DOI] [PubMed] [Google Scholar]
- doi: 10.1098/rspb.1998.0316. [DOI] [PMC free article] [Google Scholar]
- doi: 10.1098/rspb.1998.0315. [DOI] [PMC free article] [Google Scholar]
- Sillman A. J., Govardovskii V. I., Röhlich P., Southard J. A., Loew E. R. The photoreceptors and visual pigments of the garter snake (Thamnophis sirtalis): a microspectrophotometric, scanning electron microscopic and immunocytochemical study. J Comp Physiol A. 1997 Aug;181(2):89–101. doi: 10.1007/s003590050096. [DOI] [PubMed] [Google Scholar]
- Werner D. I. On the biology of Tropidurus delanonis, Baur (Iguanidae). Z Tierpsychol. 1978 Aug;47(4):337–395. doi: 10.1111/j.1439-0310.1978.tb01843.x. [DOI] [PubMed] [Google Scholar]