A groundbreaking study has revealed the genetic switches controlling the distinctive colors of the Australian finch’s red, yellow, and orange bills. Researchers from eight institutions across five countries have identified key genes that control how birds process yellow pigments from their diet.
The long-tailed finch, found primarily in northern Australia, was the focus of the study. Most finches today have bright red bills due to carotenoid pigments consumed in seeds. However, when two subspecies with different bill colors interbreed, offspring produce hybrid offspring with orange bills.
By analyzing DNA from over 900 finches, scientists discovered that yellow-billed finches lack genetic variations needed to convert yellow pigments into red ones. This finding helps understand how animals can evolve unique color signals.
Interestingly, birds use carotenoid pigments not just for color but also for vision. Researchers found that while yellow-billed finches don’t produce red pigment in their bills, they can still make it in their retinas. The study suggests that having a yellow bill may provide evolutionary advantages to these birds over many generations.
This research provides new insights into how animal coloration evolves and may help explain similar variations seen in other bird species worldwide.
Source: https://phys.org/news/2024-11-genetic-red-yellow-orange-bills.html