I am trying to figure out the relationship between 2 cardinals (males) in my yard and neighbourhood. Each time I have seen them over the last 3 days they have been seen together. One will fly into the yard, the other will follow and swoop past. If the first lands and pecks at the ground the other will fly past it 3 or 4 times. If one is in the feeder the other will try to also go to the feeder (a platform) but will not actually land. Is this a territory issue? Is one trying to show the other that he wants to be in this area and is trying to dominate? Any ideas?
This is the typical behaviour of male birds during breeding season. It's all to do with territory as you thought. Exactly the same happens here with male birds that consider my garden as part of their patch.