The Northern Cardinal is a common bird in the United States. It is the state bird of SEVEN many states. As you already know, the male of the species is a vibrant red. But you may not know that he gets that color from his food! The more red fruits and berries he eats, the redder he will become. That signifies to a female that he is healthy, making him the obvious choice for a mate. So if you want to see more Cardinals in your yard, you might think about growing some raspberries and strawberries.