At the end of January, I heard a northern cardinal sing. Birdy, birdy, birdy. What cheer, cheer, cheer. A crimson-red male sat at the top of the tree and sent out his advertisement to a nearby female.

Both male and female sing — and they do it a lot. Each has about 12 different songs. Females often, but not always, sing the same songs as their mates. Once the female is incubating the eggs, she will ...