Bluebirds’ Nests and Eggs

In all likelihood, if you discover a bluebird nest, it will be in a bluebird house.  Although bluebirds will use natural cavities, as they have throughout time, they now depend a great deal on the kindness of human landlords.  Male bluebirds arrive in late winter or early spring to look for nest sites, and most return year after year to the same locations, sometimes even the same nest boxes.  When the females arrive, the males sing to entice them to the locations they have selected.  For the most part, once a female selects her site and her mate she handles the constructing of the nest and then laying and incubating of the eggs.  The female usually finds the site she likes best and accepts the mate who has claim to this site.  The cuplike nest, loosely woven of grass, pine needles and other plant materials is often lined with fine grasses and usually houses four to six pale blue eggs.  Mountain bluebirds tend to have the palest eggs and the most eggs per clutch.  (A clutch is a group of eggs laid and incubated at the same time.)  The nestlings fledge in approximately 20 days and often the female will lay another clutch of eggs and her mate takes over the care of the fledglings.  Bluebirds’ favorite treats are peanut butter treats, suet treats and mealworms.  Once bluebirds discover mealworms at a feeder, they will keep coming back.  A birdfeeder is great but not necessary.  Place mealworms in a clean empty tuna can.  With these accommodations, the bluebirds will think themselves home at your address.