No evidence that carotenoid pigments boost either immune or antioxidant defenses in a songbird

Rebecca E. Koch, Andreas N. Kavazis, Dennis Hasselquist, Wendy R. Hood, Yufeng Zhang, Matthew B. Toomey, Geoffrey E. Hill

Research output: Contribution to journalArticleResearchpeer-review

26 Citations (Scopus)


Dietary carotenoids have been proposed to boost immune system and antioxidant functions in vertebrate animals, but studies aimed at testing these physiological functions of carotenoids have often failed to find support. Here we subject yellow canaries (Serinus canaria), which possess high levels of carotenoids in their tissue, and white recessive canaries, which possess a knockdown mutation that results in very low levels of tissue carotenoids, to oxidative and pathogen challenges. Across diverse measures of physiological performance, we detect no differences between carotenoid-rich yellow and carotenoid-deficient white canaries. These results add further challenge to the assumption that carotenoids are directly involved in supporting physiological function in vertebrate animals. While some dietary carotenoids provide indirect benefits as retinoid precursors, our observations suggest that carotenoids themselves may play little to no direct role in key physiological processes in birds.

Original languageEnglish
Article number491
Number of pages7
JournalNature Communications
Issue number1
Publication statusPublished - 1 Dec 2018


  • carotenoid
  • coloration
  • songbird
  • antioxidant
  • oxidative stress
  • honest signaling

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