Habitat - they like thickets and shrubbery to build their nests in.
Diet - although the adult birds like mainly seeds, grains and fruit, they feed their young only insects.
Lifespan - the usual lifespan of the cardinal is 3 years in the wild but some have lived a lot longer from 13 to 15 years.
Special behavior - I have watched the female sit on a branch to the side while the male visited the bird feeder. He would grab a seed and fly over to the female and feed it to her. This might be part of the their mating routine. She really seems to like being fed this way. And this goes on for quite some time!