The eastern bluebird (Sialia sialis) is a small thrush found in open woodlands, farmlands, and orchards. They are found east of the Rocky Mountains in the United States and southern Canada. Identifying an eastern bluebird is relatively straightforward once you know what to look for. Their bright blue plumage on the back and head makes them easy to spot. However, there are a few key identification features to look for to be sure you have an eastern bluebird.
Field Marks
Eastern bluebirds have several distinctive field marks that can help identify them:
Bright Blue Plumage
The most obvious field mark of an eastern bluebird is the bright blue plumage on the back and head. The blue color is fairly vibrant in males and slightly duller in females. The blue feathers can appear turquoise in certain light. When perched with wings folded, the blue plumage covers the back and most of the head.
Brick Red Throat and Breast
Male eastern bluebirds have a brick red throat and breast that is easily seen. Females have a paler, muted peach-orange color instead of the bright red. The red throat is a good way to distinguish them from the similar mountain bluebird which lacks the red throat patch.
White Belly
Eastern bluebirds have a white belly that contrasts sharply with the red breast. The white belly extends from the bottom of the breast down towards the undertail. The undertail coverts are also white.
Blue Tail
From below, the tail feathers appear completely blue. The outer tail feathers have thin white borders, but the tail is largely blue. This helps distinguish them from mountain bluebirds which have more extensive white tail edges.
Size and Shape
Paying attention to the bird’s size and shape can also aid identification:
Small Size
Eastern bluebirds are relatively small songbirds, measuring 6-8 inches in length with a wingspan around 12 inches. About the size of an American robin. Larger than a chickadee or nuthatch.
Plump Body
The body shape is plump and round compared to other bluebirds. Mountain and western bluebirds have a slimmer, more elongated body profile.
Large Head
They have a proportionately large head for the body size. The big head and plump body gives them a round, stocky appearance.
Short Tail
The tail is fairly short compared to the size of the body and wings. The short tail appears squared off when perched.
Behaviors
Eastern bluebirds exhibit some typical behaviors that can aid in identification:
Perching Posture
Often perch upright on wires, fence posts, and branches with the wings folded. The upright perching posture shows off the blue back and often the red breast.
Ground Foraging
Frequently forage on the ground in open grassy areas. Walk along the ground methodically probing for insects. Often return to the same perch between foraging bouts.
Flying Style
Direct flight style with steady wing beats. The flight path tends to be straight and level. Males sometimes perform a fluttering display flight during courtship.
Habitat
Knowing the preferred habitat of eastern bluebirds can help you know where to look for them:
Open Country
Found in open habitats including meadows, pastures, agricultural fields, parks, cemeteries, and suburban areas. Requires scattered trees, fence posts, or other perches for hunting.
Forest Edge
Frequently found along forest edges, clearings, or other transitional zones between open habitat and woodlands. Nest in tree cavities in these edge areas.
Backyards
Common in rural and suburban backyards and orchards. Use nest boxes and take advantage of bird feeders stocked with mealworms or other prey.
Range
The range of eastern bluebirds in North America can provide clues on where you’re most likely to see them:
Eastern North America
Found east of the Great Plains from southern Canada south to Mexico and Florida. At the northern edge of the range, they migrate south for winter. Southern populations are year-round residents.
Rare West of Rockies
Very rare and localized west of the Rocky Mountains where mountain and western bluebirds dominate instead. A few winter around the southwest deserts and along the Pacific coast.
Expanding North
Increasing in parts of northeastern North America as climate warms. Now regular further north in Ontario, Quebec, and the Maritime Provinces where previously rare.
Similar Species
Three other bluebird species could potentially cause confusion. Here’s how to identify them:
Mountain Bluebird
Found in western North America. Lacks the red throat patch, has a long slim body, and more extensive white edges on the tail. Males have sky blue plumage.
Western Bluebird
Also a western species. Has a gray throat and breast rather than red. Tail has white outer edges like a mountain bluebird. Females are gray-brown overall with a bluish tint.
Indigo Bunting
Despite the name, male indigo buntings are bright blue like an eastern bluebird. However, they have a conical seed-eating beak unlike the insect-eating beak of a bluebird. Found in weedy areas instead of open country.
Conclusion
The combination of brilliant blue upperparts, red or orange throat/breast, white belly, stocky body shape, upright perching posture, and open habitat preference help identify eastern bluebirds. Learning the key field marks, behaviors, distribution, and similar species makes identifying them much easier. With practice, telling an eastern bluebird from other North American species becomes quick and intuitive. The handsome plumage and cheery song of eastern bluebirds make them a backyard favorite across their range.