The northern cardinal is a medium-sized songbird, with males slightly larger than females. Males are bright red with a black mask around their red bill and a prominent crest on the top of their head. Females are olive brown with red on their wings, tail, and crest, and a red bill. Juveniles are similar in colour to females but have a black bill and a shorter crest.
Cardinals are a perfect combination of familiarity, conspicuousness, and style: a shade of red you can’t take your eyes off. Even the brown females sport a sharp crest and warm red accents. Cardinals don’t migrate and they don’t molt into a dull plumage, so they’re still breathtaking in winter’s snowy backyards. In summer, their sweet whistles are one of the first sounds of the morning. (Excerpt from The Cornell Lab of Ornithology)