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Sex steroid correlates of female-specific colouration, behaviour and reproductive state in Lake Eyre dragon lizards, Ctenophorus maculosus

journal contribution
posted on 2009-07-01, 00:00 authored by Tim Jessop, R Chan, D Stuart-Fox
In some species, females develop bright colouration to signal reproductive status and exhibit behavioural repertoires to incite male courtship and/or reduce male harassment and forced copulation. Sex steroids, including progesterone and testosterone, potentially mediate female reproductive colouration and reproductive behaviour. We measured associations among plasma profiles of testosterone and progesterone with variation in colour expression and reproductive behaviour, including unique courtship rejection behaviours, in female Lake Eyre dragon lizards, (Ctenophorus maculosus). At onset of breeding, progesterone and testosterone increased with vitellogenesis, coincident with colour intensification and sexual receptivity, indicated by acceptance of copulations. As steroid levels peaked around the inferred ovulation time, maximal colour development occurred and sexual receptivity declined. When females were gravid and exhibited maximal mate rejection behaviours, progesterone levels remained consistently high, while testosterone exhibited a discrete second peak. At oviposition, significant declines in plasma steroid levels, fading of colouration and a dramatic decrease in male rejection behaviours co-occurred. Our results indicate a generally concordant association among steroid levels, colouration, behaviour and reproductive events. However, the prolonged elevation in progesterone and a second peak of testosterone was unrelated to reproductive state or further colour change, possibly suggesting selection on females to retain high steroid levels for inducing rejection behaviours.

History

Journal

Journal of comparative physiology A

Volume

195

Issue

7

Pagination

619 - 630

Publisher

Springer

Location

Berlin, Germany

eISSN

1432-1351

Language

eng

Publication classification

C1.1 Refereed article in a scholarly journal

Copyright notice

2009, Springer