Madison, Wisconsin – A rare genetic mutation can cause northern cardinals to appear bright yellow instead of red, a change that may go unnoticed without careful observation this spring.
According to the Wisconsin Department of Natural Resources, northern cardinals typically get their red coloration from carotenoid pigments found in fruits and berries. In very rare cases, a genetic mutation prevents those pigments from converting to red, resulting in yellow feathers.
Wildlife officials say the condition is uncommon but naturally occurring. The birds are otherwise healthy cardinals and behave the same as their red counterparts.
Cardinals do not migrate and remain in Wisconsin year-round. As breeding season begins, they become more visible and vocal, making spring one of the best times to spot unusual plumage variations.
The DNR notes that cardinals forage on insects, seeds, and berries and frequently visit backyard feeders, especially those stocked with black-oil sunflower seeds.
Because the mutation is rare, many residents may overlook a yellow cardinal, mistaking it for another species.
Bird enthusiasts participating in events like the Great Backyard Bird Count or reporting observations to eBird help wildlife agencies better understand population trends and unusual sightings.
While uncommon, officials emphasize that a yellow cardinal is not a warning sign or environmental threat — simply a rare genetic variation.
Residents are encouraged to observe carefully and report notable sightings to wildlife officials.
