When it comes to spectacular displays of color, birds are obvious standouts in the natural world. Many brightly colored birds get their pigments from the foods that they eat, but that’s not true of parrots. Now, researchers reporting a study of familiar pet store parakeets — also known as budgies — have new evidence to explain how the birds produce their characteristic yellow, blue, and green feathers.

The findings reported in the journal Cell on October 5th promise to add an important dimension to evolutionary studies of parrots, the researchers say.

“Budgerigars are a great system for studying parrot colors because artificial selection over the last 150 years has resulted in a large number of simple Mendelian genetic traits that affect color,” says first author Thomas Cooke, a graduate student at Stanford University. “We identified an uncharacterized gene in budgerigars that is highly expressed in growing feathers and is capable of synthesizing the budgie’s yellow pigments.”

Scientists have studied colors in budgies for more than a century. They knew that parrots produce psittacofulvins, a type of red to yellow pigment that’s not found in any other type of vertebrate. They also knew that an inability to produce yellow pigments in some parakeets turns the birds from yellow and green to blue. But it wasn’t clear which genes and biochemical pathways were involved.

To find out in the new study, the team led by Stanford’s Carlos Bustamante first used genome-wide association mapping to identify a region containing the blue color mutation. That region contained several genes, so it wasn’t yet clear which of them was responsible.

Read the full article here.

Cell Press. ScienceDaily, 5 October 2017.