Digit ratio, polychromatism and associations with endurance and antipredator behaviour in male painted dragon lizards
Publication Type: |
Journal Article |
Year of Publication: |
2012 |
Authors: |
Michael Tobler, Mo Healey, Mats Olsson |
Publication/Journal: |
Animal Behaviour |
Keywords: |
androgen, antipredator behaviour, colour polymorphism, ctenophorus pictus, digit ratio, endurance, oestrogen, painted dragon, prenatal |
ISBN: |
0003-3472 |
Abstract:
Variation in sex hormone exposure during early embryonic development contributes to individual differences in behaviour and cognitive abilities later in life. Digit ratio has gained considerable interest as a putative marker for early androgen/oestrogen exposure in behavioural ecology research. Studying digit ratio in nonhuman laboratory as well as wild vertebrate species may be useful to assess whether different traits may be influenced by a common (e.g. endocrine-related) mechanism and whether digit ratio might be used as a phenotypic indicator for behavioural or fitness-related traits. We examined whether digit ratio (third-to-fourth toe ratio; 3D:4D) may indicate a common mechanism underlying endurance and antipredator behaviour in male painted dragon lizards, Ctenophorus pictus. We have previously shown that 3D:4D is associated with the presence/absence of a yellow throat patch (bib), with males with bibs having higher 3D:4D than those without bibs. In this study we found that 3D:4D predicted antipredator behaviour with individuals with higher 3D:4D having shorter escape response times; however, 3D:4D was not associated with endurance. Endurance and antipredator behaviour were also associated with male coloration. Males expressing a bib had shorter escape response times and lower endurance than those without a bib. Moreover, males with orange head colour had lower endurance compared to yellow-headed and uncoloured males. On the basis of these results, we speculate that the associations between antipredator behaviour, endurance, 3D:4D and male sexual coloration are caused, at least partly, by different underlying mechanisms.