I thought it was my imagination that when the Christmas season rolled around, the cardinal that came to my feeder was more brilliant red than I had ever seen before. Then I received an article from the Cornell Lab of Ornithology that made me realize what I observed was true – cardinals are redder in winter.
After the breeding season and when food is abundant, northern cardinals molt their feathers and grow new ones. During autumn molting, the cardinals look ugly, with areas of dark exposed skin and even some baldness. The ugly areas become covered with feathers tipped in gray. The gray feather tips wear off, exposing the brilliant red underfeathers. The birds reach the peak of brilliance by midwinter ahead of the spring breeding season.
The color change isn’t just for us to enjoy. It also attracts female cardinals. Studies at Cornell have shown that brighter red cardinals mate earlier and nest in better habitats, producing more offspring. The redness comes from carotenoids, pigments that occur naturally in foods such as red and purple fruits. Honeysuckle has red berries, as does dogwood and winterberry. All cardinals eat the same foods, but only the males reveal the pigments in brilliant reds.
Male cardinals are redder in winter because the genetics of the males and females are different enough to cause a color difference between the two sexes. Building a genome that produces this beautiful color is not easy. There are alternative ways males could attract females, as seen in other bird species.
Cardinals remind us that color and beauty are characteristics God has given us to enjoy. It was not an accident of some mutation that painted male cardinals red. We see amazing color in cardinals as well as peacocks, pheasants, painted buntings, parrots, splendid fairywrens, and lilac-breasted rollers, to mention just a few.
It is not your imagination that cardinals are redder in winter. Enjoy the beauty God has given us in His unique life forms in the sky.
— John N. Clayton © 2024