Bluebird or Blue Jay: What Are The Differences

Bluebirds and Blue jays are both exclusive to the Americas, primarily North America. The one obvious thing they share in common is their blue plumage, and when they make just a fleeting visit to a nearby branch or bird feeder, this can make them pretty tough to tell apart.

With a bit of knowledge and practice, telling apart these two blue coloured birds is pretty straightforward, so what are the differences between bluebirds and Blue jays?

Firstly, whilst both birds are blue, the Blue jay’s plumage is host to a broader mixture of patterns and bands, including striking black bands on their wings and tail. Contrastingly, two out of three species of bluebirds have blue upperparts and an orange-brown breast that Blue jays do not possess. Blue jays are also considerably larger, measuring around 25 to 30cm in length (9.8 to 11.8in), whereas bluebirds are around 16 to 21 cm (6.3 to 8.3in).

These are certainly not the only differences between Blue jays and bluebirds - read on to discover more ways to tell these two similar familiar North American birds apart!

Eastern Bluebird (Sialia sialis)

Blue Jay (Cyanocitta cristata)

Which is bigger, a bluebird or Blue Jay?

It’s worth pointing out that there are just one species of Blue jays, divided into four subspecies, whereas there are three species of bluebirds; the Eastern, Western and Mountain bluebird. There is another bird in the Blue Jay’s genus, though, called Steller’s Jay.

There is size variation across Blue jay subspecies and also within different species of bluebirds. In any case, Blue jays are considerably larger and heavier than bluebirds.

Bluebird measurements

• Eastern bluebirds measure 16 to 21 cm (6.3 to 8.3in) long with a wingspan of 25 to 32cm (9.8 to 12.6in). They weigh 27 to 34 g (0.95 to 1.2oz).
• Western bluebirds are slightly smaller, measuring 15 to 18cm (5.9 to 7.1in). They weigh marginally less; around 24 to 31g (0.8 to 1.1oz).
• Mountain bluebirds are around the same size as Western bluebirds but can weigh more than either of the other two bluebird species, measuring 15.5 to 18 cm (6.1 to 7.1 in) in length and weighing around 24 to 37 g (0.85 to 1.31oz).

Western Bluebird (Sialia mexicana)

Mountain Bluebird (Sialia currucoides)

Blue jay measurements

• Blue jays measure around 22 to 30cm (9 to 12in) long with a wingspan of 34 to 43cm (13 to 17in). They weigh around 70 to 100 g (2.5 to 3.5oz).
• In one study, Northern Blue Jay subspecies from Connecticut averaged 92.4g (3.26 oz) in mass, while Florida Blue jay subspecies in southern Florida averaged 73.7g (2.60oz).
• Steller’s Jay is bigger than the Blue Jay, measuring 30 to 34cm (12 to 13in) long and weighing about 100 to 140g (3.5 to 4.9oz).

As we can see, Blue jays are much, much larger than bluebirds on average. Even smaller southerly Blue jays are larger than the largest bluebirds.

Northern Blue Jay (Cyanocitta cristata bromia)

Steller’s Jay (Cyanocitta stelleri)

Which is more common, bluebirds or Blue Jays?

Both bluebirds and Blue jays live exclusively in the Americas. Blue jays extend from Canada in Quebec and Alberta all the way to Florida and Texas.

Bluebirds have a wider range, extending from South Canada all the way to Central America; Mexico, Nicaragua, Guatemala, El Salvador and Honduras.

• The Blue jay population numbers around 13 million, with 87% living in the U.S. and 13% living in Canada, and is declining.
• The Eastern bluebird population alone likely exceeds 20 million and is increasing.

Bluebirds are more common Blue jays, both in terms of their population size and distribution.

Eastern Bluebird male, in flight

Other differences between an Eastern bluebird and a Blue Jay?

Family

Bluebirds and Blue jays are not related.

Bluebirds are from the Turdidae family, commonly called the thrush family, which contains some 174 other species. A 3 species of bluebirds are from the genus Sialia.

Blue Jays are from the Corvidae family that includes other jays, jackdaws, choughs, nutcrackers, magpies, ravens and crows. Blue Jays are from the genus Cyanocitta, which contains the Blue jay and Steller's Jay. Jays are the most colourful of all the corvids.

Blue Jay in flight

Plumage

There’s no doubt that size and plumage are the primary differentiators between bluebirds and Blue jays.

Bluebirds

All bluebird species have deep or royal blue backs and upperparts with typically pale underparts that include a pink/orange/brown breast for Eastern and Western bluebirds. They also have black or brown tips on their wings. The Mountain bluebird is slightly different, as they typically lack much of the brown/orange breast and are primarily blue.

Female Eastern Bluebirds are usually a duller blue, bordering on green. They have more orangey breasts and greyish heads.

Female (left), and male (right) Eastern Bluebirds

Blue Jays

Blue jays are a similar colour blue, though slightly lighter. They have white faces, collared necks and off-white undersides. The wings and tail are perhaps their most striking feature with distinctive black bands and brighter, almost iridescent blue primary feathers. The tail feather is quite long and pronounced.

Some Blue jays, particularly the Northern Blue jay subspecies, have spurs, or small crests on the back of their heads. Blue jay plumage is highly variable, which is thought to assist the birds in identifying specific individuals.

Female Blue jays are pretty much identical to the males, if a bit smaller.

A pair of Blue Jays feeding on the ground

Bills

• Blue Jays have longer, sharper and stronger bills which are typical of corvids. They’re excellent at cracking nuts.
• Bluebirds have shorter bills typical of thrushes, and most forage softer foods like insects and berries.

Calls/Vocalisations

Blue jays have a strong repertoire of various vocalisations and are known for their sophisticated communication. As corvids, they are exceptionally intelligent.

Their calls range from alarming gull-like shrieks to warbling sounds and mimicry. They can mimic human speech and are known to mimic the calls of hawks and other birds. One of their most unique calls is referred to by birders as the “rusty pump” and sounds somewhat like a pump or gurgling noise.

Bluebirds have a much gentler, softer song, including soft warbles or chirps. For small birds, their vocalisations are actually relatively low in pitch.

A male Eastern Bluebird feeding recently fledged chicks

Behaviour

There are massive behavioural differences between bluebirds and Blue jays. Blue jays are corvids, which are known for their reasonably outward-going, brash and often aggressive behaviour. Contrastingly, many thrushes, including bluebirds, are pretty solitary, secretive and conservative.

Bluebirds do flock together in groups of 5 to 50 or so birds and form quite strong mating bonds, typically mating for life. Blue jays also mate for life, like most other corvids, and can also flock together in reasonably large groups.

Blue jays are brave, aggressive birds that are fiercely defensive of their nests. They have even been known to divebomb humans, inflicting a nasty peck! As corvids, Blue jays are exceptionally intelligent and very curious and have been known to ‘play’ with human items, like bottle caps or pieces of metal.

Bluebirds, like many thrushes, are far from stupid, but they’re not as eccentric or extroverted as Blue jays and prefer to stick to their perches or tree-top territories.

Juvenile Blue Jay, begging for food

Habitats

Both birds share similar forest and woodland habitats throughout their range. Bluebirds typically choose trees near open land and tend to make their nests in cavities, whereas Blue jays prefer taller trees. Bluebirds enjoy taking up residence in bird boxes which are often the perfect size for thrushes. Bluejays prefer to nest in tree forks some 20 feet or so above the ground.

The Mountain bluebird is notable for living at high elevations, typically above 7,000 feet, but Blue jays are certainly not afraid of heights and also live across the Rocky and Alaskan Mountains.

Blue jays tend to be more flexible with their habitats and many have settled in urban areas.

Bluebirds have a wider range and are more common in Central America; Mexico, Guatemala, Nicaragua, El Salvador and Honduras, and are more prominent in Texas, Arizona, Nevada, New Mexico, North and South Dakota, Nebraska and Kansas. Western Blue jays are more common in Utah, Idaho, Oregon, Washington and Montana. Both extend up to Alaska and Canada and are cold-hardy.

Mountain Bluebird in flight with insect in beak

Diets

Both birds are omnivorous. The Blue jay consumes around 75% plant matter, including nuts, acorns, seeds and berries. The remaining 25% is made up of insects, worms, larvae and other invertebrates of various kinds. Blue jays are resourceful feeders and have been observed fashioning tools to help them forage and feed, one example being rolled up pieces of newspaper used to scoop up food pellets that were otherwise out of reach.

Bluebirds primarily eat insects. As much of two-thirds of their diets are insects and various invertebrates, the remainder is made up of berries and seeds. They usually forage from the ground or from their tree-top perches.

Migration

Some, but not all populations of both birds migrate. Blue jays typically head southeast in winter but tend to not travel far, usually just a few hundred kilometres. Some bluebirds migrate to Mexico, but most populations don’t migrate particularly far.