Journal of Comparative Physiology B

, Volume 177, Issue 6, pp 641–654

Steroid correlates of multiple color traits in the spiny lizard, Sceloporus pyrocephalus

Original Paper

DOI: 10.1007/s00360-007-0162-7

Cite this article as:
Calisi, R.M. & Hews, D.K. J Comp Physiol B (2007) 177: 641. doi:10.1007/s00360-007-0162-7


Conspicuous coloration in females is less well studied compared to that in males. Adult female Mexican boulder spiny lizards (Sceloporus pyrocephalus) have conspicuously colored throat, or gular, regions, ranging from red to yellow, while adult males only weakly express such color in their gular region. Both sexes have dark blue–black gular stripes and venter stripes. Understanding proximate mechanisms underlying trait expression can aid in understanding trait function. To characterize the proximate mechanisms potentially influencing color variation among field-captured male and female S. pyrocephalus, we quantified three aspects of color (hue, saturation, brightness) for three body locations (gular region, gular stripes, venter stripes) and then assessed how color was related to reproductive state and concentrations of the plasma steroid hormones testosterone (T) and corticosterone (CORT) in males and T, CORT, and 17-β estradiol (E2) in females. Testes volume was not related to variation in color or in hormones, perhaps because most males were in peak reproductive condition. Large vitellogenic follicles as opposed to oviductal eggs were associated with higher E2 in females. Males with more dull gular stripes and females with dull venter stripes had significantly higher CORT. Females with red gular regions and pale grey gular stripes had higher T and E2 concentrations compared to females with a more yellow gular region and darker gular stripes. Thus, gular region color in females could communicate reproductive state; dull gular stripes in males and dull venter stripes in females could communicate stress status.


Sceloporus pyrocephalus Multiple color traits Sex steroid hormones 

Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  1. 1.Department of BiologyThe University of TexasArlingtonUSA
  2. 2.Department of Ecology and Organismal BiologyIndiana State UniversityTerre HauteUSA
  3. 3.Department of Integrative BiologyThe University of CaliforniaBerkeleyUSA

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