Warning signal properties covary with toxicity but not testosterone or aggregate carotenoids in a poison frog

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• 作者：Laura Crothers ; Ralph A. Saporito ; Justin Yeager ; Kathleen Lynch…
• 刊名：Evolutionary Ecology
• 出版年：2016
• 出版时间：August 2016
• 年：2016
• 卷：30
• 期：4
• 页码：601-621
• 全文大小：900 KB
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Life Sciences
  Evolutionary Biology
  Plant Sciences
  Human Genetics
  
• 出版者：Springer Netherlands
• ISSN：1573-8477
• 卷排序：30

文摘

Aposematic (warning) coloration is a highly conspicuous trait that is found throughout the animal kingdom. In several aposematic species, warning signals have been co-opted for use in conspecific communication systems; for example, in the toxic and bright orange Solarte population of the strawberry poison frog (Oophaga [Dendrobates] pumilio), the brightness of male warning coloration serves as a sexual signal by both attracting females and repelling rivals. Here, we investigate correlations between bright male warning coloration and several physiological characteristics (e.g., circulating testosterone and carotenoids and noxious alkaloids in the skin), to gain insights into the mechanisms underlying the signal variation in this population and to inform hypotheses regarding the evolutionary stability of this trait. We find that although measures of male brightness (viewer-dependent or viewer-independent) do not correlate with two classic correlates of sexually selected traits (circulating testosterone and aggregate carotenoids in the skin), male reflectance does show a positive correlation with concentrations of two xanthophyll carotenoids. Total reflectance (a viewer-independent measure of male brightness) also shows a negative relationship with aggregate pumiliotoxin in the skin, which is considered one of the major classes of defensive alkaloids in this species. Because the alkaloids used in this species’ chemical defense are acquired from dietary sources, the magnitude of the reflectance intensity of a male’s warning signal can potentially provide viewers with reliable information regarding territory quality, health, and/or current condition.KeywordsAposematismChemical defenseConspicuousnessOophaga [Dendrobates] pumilioSexual selectionSignal reliability