Fun facts about cardinals

The very popular Northern cardinal is the state bird of seven states, and has been introduced as a breeding species to California, Hawaii and Bermuda.

The cardinal is sexually dichromatic: The plumage of the male and female differ. Male northern cardinals are brilliant red, females primarily grayish tan.

Plumage color results from the carotenoid pigments contained in the food eaten by the birds. Brighter plumage may signal a better diet and be an indicator of mate quality. Look for brighter breasts in male birds, brighter underwing feathers in females.

Carotenoid pigments, by the way, come in yellow, orange or red. Carotene colors carrots and gives color to ripe tomatoes and autumn leaves, among other plant parts.

While the cardinals visiting your feeders come for the seeds, this species is omnivorous, eating both vegetable matter and insects.

Both male and female cardinals sing. Females singing from the nest are believed to be providing the male with information about need for food at the nest.

You see bluebird nest boxes along the road in pairs. Why two so close together? The idea is one box for tree swallows, also cavity nesters, and the second box for bluebirds. The swallows are very territorial with other swallows, but not with bluebirds. The swallows keep the second house available for bluebirds should they arrive. The two species both eat insects, but do not compete. Swallows specialize in flying insects, while bluebirds hunt on the ground.