Both sexes have pointed crests, short, rounded wings, long tails and thick, red bills. The legs and feet of the cardinal are dark red. Unlike most other birds in existence in North America today, cardinals do not migrate. North American cardinals seem to fair well year round and their southern cousins, do little traveling, either. Cold, winter months often give way to large winter flocks of cardinals, which travel close to home in groups of 70, or more, and live within a close proximity to each other.
Cardinals are probably most well-known for the whistling.
Pairs of birds can often be seen spitting out loud, clear whistling noises year round. It is not uncommon for females to counter sing with a male, whistling a duet of sorts. Some variations in song, such as accent, have been noted in cardinals living in different regions. Cardinals survive on a diet made up mostly of insects. Because of this, cardinals are often introduced into areas in North America to help control insect populations.