Libby Kolerich, age 9, of San Diego, California, for her question:

How do you tell male bird and female bluebirds apart?

The female bluebird lays the eggs and the male bluebird does most of the singing for the family. They try to keep their nest a secret and you are not likely to see the female actually laying an egg. Later, you just might spot 4 bluebird sitting on the nest to keep the precious eggs warm. But this one may be either the male or the female, for both parents take turns. If you hear a bluebird singing, while perched on a twig near the nest, chances are he is a male.

Mr. and Mrs. Bluebird wear matching outfits and you cannot tell which is which by looking at them. They wear mostly blue, with rusty red bibs and white weskits. The western bluebirds wear blue bibs under their chins and the reddish chestnut color of their weskits spreads back onto their shoulders. All the pretty bluebirds, male and female, wear the colors of the American Flag    red on their breasts, white on their tummies and heavenly blue on their backs.