The Northern cardinal (Cardinalis cardinalis) is one of the most recognizable birds throughout its range, especially the males. Who could mistake their brilliant red coloring and the iconic tuft crowning their heads? By no means are the females dull to look at either, with soft, doe-colored feathers trimmed with a deep red. You have likely admired how beautifully they stand out against a fresh blanket of snow. Has it ever struck you as odd, though, that these birds are present year-round?
Cardinals stay in their territories year-round, meaning they do not migrate. Surprisingly, this is true even in the northernmost regions of its range, which borders Canada! Perhaps even more surprisingly, the cardinal has not historically called the far northern states home. It has extended its range farther north since the early 1900s, likely due to increased food availability.
Now I bet you have a dozen questions related to why the Northern cardinal is not migratory and how in the world they stay warm in Wisconsin during winter. Read on to find out!
Northern Cardinals are non-migratory birds
The short answer to the question of why cardinals do not migrate is food availability. The diet of the Northern cardinal consists of insects and seeds from berries, flowers, grasses, and grain. While many bird species must migrate due to food scarcity in the winter months, cardinals are still able to forage for certain insects and types of seeds.
With food sources readily available, it is not worth it for the cardinal to expend the enormous amount of energy required to migrate. Instead, these small but mighty birds convert their food sources into energy that helps them survive harsh winters.
Food availability is also the answer to why cardinals have extended their home range north. With the popularization of bird feeders, year-round food sources increased, which allowed the birds to live comfortably in colder regions.
Male Cardinal eating berries from a tree
The range of the Northern cardinal extends across the U.S. from the east coast to the central plains. It also covers a portion of the desert southwest and parts of Mexico. The individual territories of these birds are typically 2-10 acres. Cardinals prefer to stay within a mile of their home range throughout all seasons.
Unless the weather is too harsh, cardinals remain active throughout the winter months. They will rove their territories in search of food to keep their energy levels high. For warmth, cardinals can control their body temperature. The most common ways they do this include fluffing their feathers and changing feather positions. In more extreme cold temperatures, cardinals may change the direction of their blood flow or intentionally shiver to increase their body temperature.
When the weather conditions are not agreeable, cardinals may seek shelter in dense groves of vegetation, usually low shrubs. They are not cavity nesters and, thus, will not enter birdhouses or tree cavities.
Northern Cardinal during winter
Adult Northern cardinals spend their entire lives within their home range. These birds likely wander the most as juveniles. They begin to leave the nest after about ten days and stay with their parents until able to obtain food on their own. Then the young cardinals set out to find a permanent territory of their own.
One reason staying in place works so well for the cardinal could be that they are habitat generalists. Meaning, it is relatively easy for them to find food within their range, and they are not particular about where they nest. Cardinals will build nests in open woodlands, dense shrubs, and hedges in your backyard. They will even tolerate busy suburbs and deserts environments.
The fact that these birds are permanent residents wherever they call home may be why they are the state bird of no less than seven U.S. states. The cardinal is also the mascot of numerous school sports teams. It makes sense knowing the tough the conditions these birds withstand and how successful they are as a species.
Female Northern Cardinal
Have you ever wondered if the brilliant coloration of a male cardinal makes him a bigger target for predators? It seems like natural selection has made a mistake, especially considering a male’s feathers do not dull even in winter when he stands out the most. However, there are other contributing factors to consider.
As with many other avian species, a male cardinal's bright coloring works in his favor when finding a mate. Brightness is a sign of reproductive success. It is also related to how much food access the male has. To females, this acts as a signal that a particular male is healthy and possesses good territory with plenty of food availability.
The term for this process is known as sexual selection. Because cardinal females consistently choose brighter males as mates, evolution took the path of reproductive success over playing it safe with better camouflage. On the other hand, females have evolved to blend in well with their surroundings. Which ensures they have higher reproductive success rates by their ability to camouflage the nest more easily.
Male (right) and female (left) Northern Cardinals perched on a branch
Just because a male cardinal's brightness makes him a successful and sought-after mate does not mean they are not also obvious targets to predators. They most certainly are. However, it does not seem to have a major effect on the species as a whole.
Cardinals tend to have higher survival rates than other species, possibly because they are such habitat generalists. Being non-migratory could be a factor as well. They endure less stress. Plus, staying in one place allows the cardinals longer breeding seasons. Which, in turn, makes space for higher rates of nesting success.
The Northern Cardinal is a truly fascinating species. The way they have adapted over the past century to not only survive but expand and thrive in new, not to mention colder, territories is remarkable. I hope the next time you see a cardinal perched at your bird feeder or filling the forest with song, you have an even greater admiration for this mighty little bird.
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