Evolutionary Ecology

, Volume 30, Issue 4, pp 601–621 | Cite as

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

  • Laura CrothersEmail author
  • Ralph A. Saporito
  • Justin Yeager
  • Kathleen Lynch
  • Caitlin Friesen
  • Corinne L. Richards-Zawacki
  • Kevin McGraw
  • Molly Cummings
Original Paper


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.


Aposematism Chemical defense Conspicuousness Oophaga [Dendrobates] pumilio Sexual selection Signal reliability 



This work complied with ANAM SE/A-112-08, SE/A-27-09, SEX/A-58-09, SE/A-30-11 and SE/A-36-12 permits, and UT 07092101 and AUP-2010-00139, Tulane 0382R and STRI 2008-03-12-05-2008 IACUC protocols. We thank Christina Buelow, Victoria Flores, Sara Mason and Anna Deasey for their exceptional field help, and Clyde and Wilson Stephens for the generous use of their property over the years. Special thanks to Hans Hofmann, Daniel Bolnick, Michael Ryan, Kyle Summers, William Wcislo, John Christy, and David Cannatella for their advice on experimental protocols. Finally, we thank two anonymous reviewers and the editors for helpful comments on previous versions of this manuscript. L.C. was supported by a UT EEB grant, NSF DDIG #IOS 1110503, a Smithsonian Tropical Research Institute A. Stanley Rand fellowship, an Animal Behavior Society Barlow Student Research Award, and an American Association of University Women fellowship. L.C. and M.C. were supported by a National Geographic Society Committee for Research and Exploration grant.

Supplementary material

10682_2016_9830_MOESM1_ESM.docx (123 kb)
Supplementary material 1 (DOCX 122 kb)


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Copyright information

© Springer International Publishing Switzerland 2016

Authors and Affiliations

  • Laura Crothers
    • 1
    Email author
  • Ralph A. Saporito
    • 2
  • Justin Yeager
    • 3
  • Kathleen Lynch
    • 4
  • Caitlin Friesen
    • 5
  • Corinne L. Richards-Zawacki
    • 6
    • 7
  • Kevin McGraw
    • 8
  • Molly Cummings
    • 5
  1. 1.University of California, DavisDavisUSA
  2. 2.Department of BiologyJohn Carroll UniversityUniversity HeightsUSA
  3. 3.Department of Ecology and Evolutionary BiologyTulane UniversityNew OrleansUSA
  4. 4.Department of BiologyHofstra UniversityHempsteadUSA
  5. 5.Department of Integrative BiologyUniversity of Texas at AustinAustinUSA
  6. 6.Department of Biological SciencesUniversity of PittsburghPittsburgUSA
  7. 7.Smithsonian Tropical Research InstitutePanamáRepublic of Panama
  8. 8.School of Life SciencesArizona State UniversityTempeUSA

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