Cardinals are one of the most commonly spotted birds in the United States. In fact, such is the popularity of these birds that seven states in America have the cardinal as their state bird, including Ohio and North Carolina.
However, what really sets these birds apart from other songbirds is their vibrant red color.
Why are cardinals red? Their richly colored plumage is a result of the carotenoid content in their food. Because of the abundance of fruits and berries in their diet, cardinals flaunt brilliantly red plumes. The male cardinal’s bright plumage plays a key role in attracting a female partner.
This article will tell everything you need to know about the male cardinal’s red plumage, including the scientific reason behind it. We will also discuss how you can help them maintain their feathers.
Why cardinals have red feathers: explained
There are two basic mechanisms that produce the colors that are displayed on the feathers of all birds:
The structural properties of all birds’ feathers can act in a way similar to a prism. When light falls on the feathers, they scatter, refract and reflect the light to give all the individual feathers their own colors.
However, this is a secondary cause for the brilliantly colored feathers of a cardinal. Read on to know the primary reason behind it.
Fun fact: It is the structural feature of their feathers that bestow many birds with iridescence or the blue color that they have.
Pigments are chemical compounds that provide the coloration in a bird’s feathers. They give colors to objects in relation to the light wavelength that they reflect and absorb.
Cardinals’ feathers have red pigment in them that reflects the wavelength for the color red, absorbing all the other colors. There are three specific pigments that provide coloration to a cardinal’s body:
Porphyrins are created by amino acid modification. They are the rarest of the three pigments present in a bird’s body. They can produce colors like green, brown, red, and pink.
If you know anything about human skin color, you might already know what melanin is since it is exactly what gives color to the human skin.
What you might not know, however, is that melanin is also present in the skin and feathers of all birds. Melanin can produce a variety of colors ranging from reddish-brown, dark brown, red, black, and pale yellow.
Depending on the location and the concentration of the melanin, it is also responsible for giving strength and durability to the feathers of all birds.
Carotenoids give the birds their vivid reds, oranges, bright yellows. Carotenoids and melanin often react together to produce more intricate hues, such as olive greens.
Fun fact: Did you know that carrots are named after the abundance of carotenoids in them? Carotenoids are responsible for their vivid orange coloring. So, if you had too many carrots for a week or two, your skin might actually turn orange!
The role of carotenoids in Cardinals’ feathers
In the previous section, we discussed the coloration in a cardinal’s body. Now, we’ll talk about what exactly provides these little birds their vivid color and precisely how it happens.
The reason behind the red color of a cardinal’s feathers can be mapped down to their carotenoid-rich diet. The stunning red-colored berries that grow on dogwood trees are a favorite of these birds. These fruits also happen to be rich in carotenoids.
Along with other red-colored, carotenoid-rich foods that a cardinal consumes, the berries are metabolized in their bloodstream to the growing follicles of their feathers.
Although the fully grown feathers cannot be affected by the carotenoids, the pigment gives its color to the new ones.
However, if the cardinals do not maintain their carotenoid-rich diet, their feathers will grow dull after they molt.
Why do the female and amateur male cardinals not have red feathers?
The female cardinals have a pale brown body, with warm reddish accentuations near the tail, crest, and wings, with the juveniles taking after them.
It might make one wonder why the female and amateur male cardinals have mutely shaded skin and feathers, unlike the bright plumage of the adult males. After all, they have the same diet, especially the females.
It is because their dull coloring is more suitable for their survival since they can blend in with their surroundings and avoid predators.
Not only the cardinals but many in different bird species, the males are more brightly colored than the females. Their coloration also helps them attract a female partner during their mating season.
How do the feathers of cardinals get redder during winters?
You might know that cardinals suffer from feather wear every year during the winters.
However, a strange difference has been noticed in the feathers of a cardinal during winters. Many birdwatchers have reported that their feathers appear a brighter shade of red in these months.
Do you think so, too? If so, what could be causing it? Don’t worry. Even if the feathers of male cardinals are actually redder during the winters, it has nothing to do with the cold.
Like we mentioned before, the primary cause for the color of a cardinal’s feather is carotenoids. So, it is probable that the cardinals start eating more carotenoid-packed food during winters, which leads to their brighter coloration.
The significance of red feathers among the cardinals
Besides the fact that the bright red cardinals are a sight to behold, their red color also helps them during their mating season when they are trying to attract a female.
The brightness of a male cardinal’s feathers greatly influences the choice of their prospective partner. If a male cardinal has bright red plumes, it indicates that they are fit and healthy.
It also shows that they can find the best sources of food that are rich in protein and other nutrients, including carotenoid pigments, for both the female and their babies. Moreover, said cardinal is likely to hold a superior territory and offer better parental care.
A duller male signifies that he doesn’t have the strength or health to maintain a good enough territory or procure sufficient quality food for themselves or their family.
Are there white cardinals? (Albino and leucistic cardinals)
Have you ever come across a pale or even white bird that looks like a cardinal but is white-washed? Like humans, some cardinals may also lack the melanin pigment in their feathers, resulting in their light or white-colored feathers.
If an albino or leucistic cardinal has a carotenoid-rich diet, though, their feathers would be a unique, gentle pink. Although pure albinism in cardinals is quite rare, partial albinism and leucism can be seen pretty often.
Cardinals that are genuinely albino have a very short lifespan in the wild since their eyes are not strong enough. In addition to adding color to their skin, melanin also strengthens their eyesight and protects them from the harmful (ultraviolet) rays of the sun.
Leucism is another strange skin condition in cardinals where their skin retains some melanin, resulting in patchy and pale skin and even white feathers.
However, leucism doesn’t affect their eyesight, rendering them a comparatively longer lifespan than genuinely albino cardinals.
How can you help cardinals maintain their red feathers?
Do you wish to help these birds retain their brilliantly red color? There are certain changes you can make to your backyard that help these birds with it.
Cardinals are a sucker for native fruits and berries (most native fruits are packed with carotenoids). You can plant wild grapes, raspberries, or even an apple tree if that is what’s convenient for you.
However, the berries from the dogwood trees are by far the favorite treats for these cardinals everywhere. These trees flower in white, although shades pink and purple are often spotted.
Regardless of the color of their flowers, the stunning red berries of these trees will keep the cardinals coming back for more.
If you wish to put out seeds for the cardinals, black oil sunflower seeds might be a good choice, especially during the winters.
This is because these birds tend to forage high-protein food like insects in the summers for the cold winter season. To add variety to their diet, you can also mix some safflower seeds that are another rich source of carotenoids.
Frequently asked questions
Why are some cardinals yellow?
Their yellow plumage may be caused by a genetic issue called xanthochromism, where there is an unusual lack of pigmentation in the cardinal. It can mean a lack of red pigmentation, which is then replaced by yellow. It can also be related to the bird’s diet (a lack of carotenoids).
When do baby cardinals turn red?
When the young fledglings grow their first feathers during the fall, they look brown with some red accentuation. However, the young male cardinals will turn fully red only after reaching maturity and molting their feathers at around 12 months old.
To every curious birder who wanted to learn the secret behind the brilliant red plumage of the male cardinals, the answer lies in their carotene-rich diet. The more carotene they will consume, the brighter they will appear.
However, the female and juvenile cardinals do not take after the males’ coloration because their dull appearance makes them easier to remain undetected.