In this picture you can see that the female in the foreground, has more of an olive-brown body with a touch of red on her crest, wings and tail.
Juveniles have a brown body, a black bill and no black on the facial area.
Cardinals are territorial birds and easily become one of the dominant feeders at the bird feeder.
I have seen many occasions in my own garden when even the sight of their own reflection can trigger a fight!
One male that frequents our garden, spent the whole of one Spring attacking himself in the side mirror of one of our cars - he was quite determined that the other bird was not going to get the better of him!
These birds search from the ground up for seeds, fruits, and berries of several species of plants, as well as insects, during breeding season.
They do like sunflower seeds when friendly humans supply them at bird-feeders.
Females usually lay 3 to 4 pale green eggs, spotted with red-brown, in a nest of woven twigs and plant fibres, which is mainly built by the female.
The nest is usually well hidden in thick brush between 3 and 10 feet from the ground.
Often a pair will lay two clutches of eggs each summer. Incubation takes around 12 to 13 days and the female incubates the eggs.