The Northern Cardinal (Cardinalis cardinalis) is a familiar and admired bird across North American backyards. Its striking presence often prompts interest in distinguishing between males and females, a common inquiry for both seasoned birdwatchers and casual observers.
Plumage: The Most Obvious Clue
The most apparent characteristic for differentiating male and female Northern Cardinals is their plumage coloration. Adult male Northern Cardinals display a brilliant, uniform red across their entire body, a color so intense it inspired their name, referencing the robes of Catholic cardinals. The male also possesses a distinct black mask that encircles its eyes and covers the area around its bill. This bold coloration serves to attract mates and signal territorial claims.
In contrast, the adult female Northern Cardinal exhibits a more subdued, reddish-brown or olive-brown hue, providing natural camouflage, especially during nesting. She features reddish accents, particularly noticeable on her wings, tail, and crest. Like the male, the female also has a blackish mask around her eyes, though it is often less defined and lighter than the male’s.
Subtler Physical Indicators
Beyond plumage, other physical traits can offer clues to a cardinal’s sex. While both sexes possess a prominent crest, the male’s often appears more upright and vibrant. The female’s crest might be slightly less pronounced.
Differences in size are generally subtle, but males tend to be slightly larger and more robust than females.
Another distinguishing feature lies in the beak coloration. Both sexes have a chunky, cone-shaped bill, but the male’s is typically a brighter, more uniform orange-red. The female’s beak might be a slightly duller or more muted orange, particularly near the base.
Behavioral Cues
Observing certain behaviors can also help in sex determination. Male Northern Cardinals are known for their frequent and varied singing, often used to attract mates and defend their breeding territory. Their songs are typically loud, clear whistles, which can speed up or slow down. Males may sing throughout the year, with peak vocalizations occurring in spring and early summer.
Female Northern Cardinals also sing, a trait not common among many North American songbirds. Her song is often more complex and can be sung from the nest, serving as a communication signal to the male, possibly indicating a need for food. During the breeding season, the male often feeds the female while she incubates the eggs. He also assists in bringing nesting materials, though the female is the primary builder of the nest.