Cardinals are one of the most beloved and recognizable backyard birds in North America. The bright red plumage of the male northern cardinal is a vivid splash of color against the winter landscape. However, yellow cardinals are exceptionally rare. So why are yellow cardinals so uncommon compared to the ubiquitous red cardinal?
What Makes a Cardinal Yellow
Cardinals owe their red coloration to carotenoid pigments obtained from their diet of seeds and fruit. The most common carotenoid in cardinals is astaxanthin, which produces a vibrant red hue. However, yellow cardinals get their distinctive color from a different carotenoid called lutein. This pigment is much rarer in the cardinal diet, leading to the scarcity of yellow cardinals.
There are three primary ways a cardinal can end up yellow:
- Diet – A small percentage of cardinals retain the ability to metabolize lutein instead of astaxanthin. If their diet lacks red pigments, they will turn yellow instead.
- Color Mutation – Genetic mutations can prevent cardinals from properly metabolizing red pigments, resulting in plumage tinted yellow.
- Leucism – A rare condition that inhibits melanin and carotenoid pigment production. This can produce yellow or white cardinals instead of red.
While unusual, yellow cardinals are considered natural color variants and not hybrids or artificially colored birds.
Geographic Distribution of Yellow Cardinals
Estimates suggest that yellow cardinals occur at a rate of 1 in 1 million. Their rarity means they can turn up anywhere within the cardinal’s wide range in eastern North America.
However, certain areas seem to boast higher numbers of reported sightings, including:
- Southeast – Florida, Georgia, and South Carolina have a relatively high frequency of yellow cardinal sightings.
- Northeast – New York state and New Jersey also regularly report yellow cardinals, especially in winter months.
- Midwest – Scattered sightings have been reported from Ohio, Indiana, Illinois, and other Great Lakes states.
The Southeast’s humid, warm climate may promote better lutein production from vegetation. And New York and New Jersey’s proximity to major migration routes increases the odds of sighting a wandering yellow cardinal.
Why Yellow Cardinals Are Rare
Several key factors contribute to the scarcity of yellow cardinals compared to their bright red relatives:
Dietary Preference for Red Pigments
Astaxanthin produces a stronger, richer red coloration than lutein-based yellows.Cardinals seem to preferentially select red pigments from their environment when given a choice.
Need for Mutations in Metabolism
The ability to metabolize lutein over more common red carotenoids requires genetic mutations affecting pigment assimilation. These are relatively rare.
Camouflage Disadvantage
Yellow cardinals, especially females, are more vulnerable to predators than camouflaged red birds. Lower survival can reduce their numbers over generations.
Competition from House Finches
Abundant yellow house finches may outcompete rare yellow cardinals when red pigments are limited.
Lutein Availability
While lutein is present across cardinal habitats, it occurs at much lower levels than other pigments. Scarcity of lutein in the environment limits yellow coloration.
Notable Yellow Cardinal Sightings
Due to their scarcity, sightings of yellow cardinals often generate interest from birders and the public:
Port St. Lucie, Florida
In 2012, Port St. Lucie residents were treated to regular sightings of a yellow cardinal appropriately dubbed “Sunny.” Sunny’s bright coloration earned it local celebrity status.
Alabama Yellow Cardinals
Alabama has produced an unusually high number of yellow cardinal reports over the years. Several individual birds have been spotted repeatedly at backyard feeders.
Lewisburg, Pennsylvania
In 2021, a bright yellow cardinal nicknamed “Sunny” became a sensation after building a nest near Lewisburg. Sunny and its mate raised three broods of cardinal chicks.
Toronto, Canada
Canada’s first documented sighting of a yellow cardinal came in 2020 when a bright male turned up at a backyard feeder outside Toronto. Birders flocked for a glimpse.
Efforts to Attract Yellow Cardinals
Because of their popularity, some people try strategies to lure yellow cardinals to their feeders. These include:
- Offering a diet rich in yellow petals and lutein-producing flowers
- Providing yellow feeders and houses that appeal to yellow birds
- Using yellow bird baths, which may entice passing yellow cardinals
- Planting yellow native berries and shrubs known to attract cardinals
- Avoiding red-colored feeders and houses that repel yellow mutants
However, there is no guaranteed way to attract yellow cardinals. Due to their genetics and behaviors, they will remain an exciting rarity among North America’s birdwatchers.
Conclusion
Yellow cardinals are one of the rarest color variants of one of America’s favorite backyard birds. Their striking yellow plumage arises from an uncommon diet, genetic mutations, or conditions like leucism. Preference for red pigments, camouflage needs, and competition from other birds likely all work together to maintain the scarcity of yellow cardinals. Yet hope remains that bird lovers will be treated to a flash of yellow in their gardens as these special cardinals continue to turn up in isolated sightings across North America.