Northern cardinals are medium-sized songbirds. Both males and females have thick, bright orange, cone-shaped beaks. They also have a long tail and a pointed crest of feathers on the top of their heads. Males are bright red all over except for a large, black mask on their face. The mask covers their eyes, goes around their beaks, and covers their throats so that it looks like a black bib. Females are light brown with a reddish crest, wings, and tails. Females have a very small, black mask and bib. Males are slightly larger than females. Young cardinals look similar to females, but they have a gray-black bill and have less red coloration.

Northern cardinals measure 20.9 to 23.5 cm long and weigh 42 to 48 g. Their wingspans measure 30.5 cm from tip to tip.

Range mass: 42 to 48 g.

Range length: 20.9 to 23.5 cm.

Average wingspan: 30.5 cm.

Other Physical Features: endothermic ; homoiothermic; bilateral symmetry ; polymorphic

Sexual Dimorphism: male larger; sexes colored or patterned differently; male more colorful

Average basal metabolic rate: 0.5163 W.