The darker shade of grey including Mexico is where the Eastern Bluebird stays all year, the lighter color to the north is where some bluebirds head for spring, and the light shade of grey to the east of the darker area is the location where it may reach out during the winter months.
Eastern Bluebird has 1-3 broods a year with a clutch size of 2-7 eggs that are mostly blue but can be white. Incubation period is 11-19 days and nestling period is 17-21 days.
The diet is mostly insects and berries, such as crickets, grasshoppers, spiders, earthworms, and many others.
If you want to attract the Eastern Bluebird to your yard by feeding them, listed below are some food options these birds prefer.
Eastern Bluebirds have been known to use a variety of bird feeders. But the two types of bird feeders listed below, are feeders the Eastern Bluebird prefers. The pictures below are some examples.
Any type of mealworm feeder can be used. Some mealworm feeders may not work as well as others to attract the bluebird to your yard. Watch this video how one birder was able to train bluebirds to eat from his feeder. "How To Train Bluebirds"
Any size, shape or style can be used. All the food mentioned above can be placed on a platform feeder; also known as a tray feeder or fly thru feeder.
Any size, shape or design with the interior dimensions of a 5" x 5" floor to a 5.5" x 5.5" floor. Interior height 8"-12". Entry hole 1.5" diameter that is 6"-10" above the floor. You can place your house 4'-6' high facing the entry hole to the east towards an open area. If you plan to to place more than one box for the Eastern Bluebird, place your nest boxes 300' apart to avoid territorial denomination.
Pictures below are some examples of Eastern Bluebird houses.
Some bluebird houses are sold with an oval hole or a slot at the top, like the pictures above.