Boston, Massachusetts – A rare genetic mutation could cause a bright yellow northern cardinal to appear in Massachusetts backyards this spring, an occurrence ornithologists estimate may happen in roughly one in a million birds.
Northern cardinals are best known for the male’s vivid red feathers, a color produced by carotenoid pigments found in fruits and berries. Experts say that in extremely rare cases, a genetic mutation prevents those pigments from converting to red, resulting in yellow plumage instead.
Though uncommon, documented sightings continue to surface across the United States. Two of the most recent confirmed reports occurred in Bath, Michigan, in 2024 and in the St. Louis, Missouri, area in 2025.
Wildlife specialists emphasize that yellow cardinals are not a separate species and are not linked to environmental hazards. They are healthy northern cardinals displaying a naturally occurring genetic variation.
Cardinals remain in Massachusetts year-round and become more active during spring breeding season, increasing visibility in neighborhoods and wooded areas. The birds frequently visit backyard feeders, especially those stocked with black-oil sunflower seeds.
Residents who observe unusual coloration are encouraged to document sightings through bird-monitoring platforms such as eBird, which help researchers track rare occurrences.
While the odds remain extremely low, experts say careful observation this season could reveal one of the rarest backyard bird variations in North America.
