Maternal nutrition affects reproductive output and sex allocation in a lizard with environmental sex determination

Daniel A. Warner*, Matthew B. Lovern, Richard Shine

*Corresponding author for this work

Research output: Contribution to journalArticle

84 Citations (Scopus)

Abstract

Life-history traits such as offspring size, number and sex ratio are affected by maternal feeding rates in many kinds of animals, but the consequences of variation in maternal diet quality (rather than quantity) are poorly understood. We manipulated dietary quality of reproducing female lizards (Amphibolurus muricatus; Agamidae), a species with temperature-dependent sex determination, to examine strategies of reproductive allocation. Females maintained on a poor-quality diet produced fewer clutches but massively (twofold) larger eggs with lower concentrations of yolk testosterone than did conspecific females given a high-quality diet. Although all eggs were incubated at the same temperature, and yolk steroid hormone levels were not correlated with offspring sex, the nutrient-deprived females produced highly male-biased sex ratios among their offspring. These responses to maternal nutrition generate a link between sex and offspring size, in a direction likely to enhance maternal fitness if large body size enhances reproductive success more in sons than in daughters (as seems plausible, given the mating system of this species). Overall, our results show that sex determination in these animals is more complex, and responsive to a wider range of environmental cues, than that suggested by the classification of 'environmental sex determination'.

Original languageEnglish
Pages (from-to)883-890
Number of pages8
JournalProceedings of the Royal Society B: Biological Sciences
Volume274
Issue number1611
DOIs
Publication statusPublished - 22 Mar 2007
Externally publishedYes

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Keywords

  • Amphibolurus muricatus
  • dietary quality
  • maternal effects
  • sex ratio
  • temperature-dependent sex determination
  • yolk steroid hormones

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