More fun facts that I just learned: cardinals mate between March and September, and they build their nests in bushes and dense shrubs low to the ground. That's exactly where I spotted this fellow, and within moments the female popped her head out, too!
@ludwigsdiana Hi Diana. The cardinals were in a bush about 2 feet (60 cm) from the ground, but the bush was on a hill, so I could see them from below without having to squat low. As Wendy @wendyfrost said, it's good to know where they will possibly be nesting. Maybe I will be lucky enough to capture some babies later on :)