Cardinals are my favourite winter bird. Their bright colours always liven up a dull day. I have a pair (male and female) who come to my backyard feeders. I think the male has been in my area for a couple of years, starting as an immature male and finally finding a mate possibly just this year. At least I like to think it is the same bird and that he has happily found a female. I do know that cardinals are territorial and often an area is inhabited by one pair. Not sure of area size though.