Why Red?

A red streak flashed by my window. One of the cardinals that live in and around my yard on its way to somewhere in a hurry. As another paid a brief visit to a hanging flowerpot on my porch, it made me wonder why are cardinals red? Red is not a color I would choose if I needed to avoid the attention of predators, but red they are. Oh, I know, it’s said the males are red to attract the females, but little brown wrens and sparrows seem to be doing fine as far as the breeding business goes. So, if cardinals are red for no other reason than to make you and me happy, that’s good enough for me.