About This Project

Zebra Finches use bright orange-red pigments called carotenoids, derived from their diet and made usable in mitochondria, in the colors of their beaks and legs. These displays are used by males to attract mates. Our aim is to lower the function of mitochondria in Zebra Finch males, and to observe the effect this has on carotenoid production. If there is a decrease in production, this will be evidence that carotenoid-based displays could be honest signals to females of mitochondrial fitness.

Ask the Scientists

What is the context of this research?

The foundation of this project is built on a simple idea in wildlife biology: females of many species often use colorful displays to choose an individual with which to mate. Many types of finches, including the zebra finch, use red carotenoid pigments in their mating ornamentations. While it is known that females use these displays to choose the "most fit" mates, it is not well defined what type of "fitness" is being signaled to the female. Researchers now suggest that carotenoid production may be tied to the function of energy producing mitochondria in eukaryotic cells. We can then hypothesize that only individuals with healthy mitochondria will be able to devote energy to developing carotenoid displays making the ornamentations an honest signal to females of male respiratory health.

What is the significance of this project?

The recognition of the importance of the mitochondria in uncovering the secrets of the evolutionary history of eukaryotic organisms is spreading rapidly. If a causal link between mitochondrial function and carotenoid production can be found, more evidence is added to the growing hypothesis that mate choice using ornamentation is a deeper process than we previously thought possible. If carotenoid based ornamentation is in fact an honest signal for the healthy function of mitochondria, females could essentially be assessing males for respiratory fitness. This could shed light on the evolution of mate choice in eukaryotic organisms. Mate selection could have evolved with mitochondria as a driving force behind it.

What are the goals of the project?

All funds will be devoted to paying for supplies and analyses necessary for project completion. Once IACUC forms are submitted to our institution at Auburn University we plan to begin research early 2017, preferably in January. We plan to publish our results upon project completion.

Our experimental design will consist of two groups of 18-20 male zebra finches housed in pairs in 1 square meter approved enclosures. The birds will separated in two groups, one fed Mazuri food pellets with supplement to induce mitochondria membrane dysfunction and a control group fed food without the supplement. At the end of three weeks, carotenoid coloration and concentration of the birds will be determined using photography, portable spectrometry, and HPLC.