Extremely Rare Yellow Cardinal

'One in a million' yellow cardinal
spotted in Alabama

An extremely rare cardinal has birders and biologists flocking to Shelby County, Alabama. Auburn University biology professor Geoffrey Hill said the cardinal is an adult male in the same species as the common red cardinal, but carries a genetic mutation that causes what would normally be brilliant red feathers to be bright yellow instead.

Alabaster resident Charlie Stephenson noticed the unusual bird at her backyard feeder. She said she's been birding for decades but it took her some time to figure out what she was seeing.

"I thought 'well there's a bird I've never seen before'," Stephenson said. "Then I realized it was a cardinal, and it was a yellow cardinal."

"Every time I watch the bird feeder, I can see him," she said. "The cardinals in my back yard typically come in the morning and again in the evening and I can only bird-watch on weekends until the time changes, but on weekends, I'll sit there and watch for him.” She added, "Every time we've looked for him, he'll show up at least once that day."

Professor Hill, who has written books on bird coloration, said the mutation is rare enough that even he, as a bird curator and researcher has never seen one in person.

"I've been birdwatching in the range of cardinals for 40 years and I've never seen a yellow bird in the wild," Hill said. "I would estimate that in any given year there are two or three yellow cardinals at backyard feeding stations somewhere in the U.S. or Canada.”

"There are probably a million bird feeding stations in that area so very very roughly, cardinals are a one in a million mutation that causes its feathers to be yellow instead of red.”

Hill said that cardinals and other songbirds need to consume substances called carotenoids (found in sweet potatoes and carrots) from the environment around them to achieve their bright colors.

"Songbirds like cardinals almost never consume red pigments; rather they consume abundant yellow pigments," Hill said. "So, to be red, cardinals have to biochemically convert yellow pigments to red."

Hill was part of the research team that identified the enzyme -- called CYP2J19 -- that, for most cardinals, converts all that yellow pigment into red feathers.

Resident and bird-watcher Stephenson said she hadn't realized how rare the bird was when she saw it. "I'm used to being a birder and you see some leukocytic ones, you see some albino ones," she said. "But I thought this was something else and then I learned how rare it is."