I had quite a few cardinals, Indiana's state bird, this winter. Put out lots of sunflower seed. But they are very timid birds. Everything chases them away. They don't seem to flock, and operate as male - females pairs at most.
I usually have lots of house sparrows. Not so many this year. But had an increase in dark eyed juncos, which are a little smaller. There were some interesting turf wars between the 2.
Most of the birds flee from the bluejays, which I've learned are predatory. The only birds that consistently stand their ground are the various wood peckers. One jab from their beaks, and everything moves away quickly.