Mountain Bluebird

Quick Take

• This bird forms monogamous pairs every breeding season, though it has no compunction about mating outside that bond. Breeding behavior details →
• The mountain bluebird migrates farther than any other bluebird, and yet it isn't even a social species. Migration and social patterns →
• It can't excavate its own nest, which creates a survival problem most people wouldn't think to ask about. How nesting works →
• Its first clutch of chicks sometimes sticks around after fledging, though not for the reason you would expect. Chick development after fledging →

The mountain bluebird makes its home in the pristine landscapes of the western Americas. Sporting an elegant, bright blue plumage, this species can be seen perching on fence posts, wires, and trees, where it makes a loud warbling sound. This is one of the most quintessential and widespread songbirds in western North America.

4 Amazing Mountain Bluebird Facts

• The mountain bluebird is the official state bird of Idaho and Nevada. Some Native Americans consider the feathers to be sacred symbols.
• This species is sometimes called “the bluest of the bluebirds” for its particularly bright blue plumage. Other common names include the Arctic bluebird and the ultramarine bluebird.
• The mountain bluebird can produce hybrid offspring with the closely related eastern and western bluebirds.
• The mountain bluebird belongs to the family Turdidae, which includes thrushes and bluebirds.

Where to Find the Mountain Bluebird

The mountain bluebird can be found in the grasslands, deserts, mountains, and farmlands of western Canada, the United States, and Mexico, usually at elevations above 7,000 feet.

Nests

Mountain bluebirds prefer the hollow cavities of conifers and aspens for their nesting sites. If these are not available, then they may choose cliffs or banks instead. These birds cannot create hollows and holes themselves, so they instead rely on cavities created by both natural and artificial means.

Classification and Scientific Name

The scientific name of the mountain bluebird is Sialia currucoides in the family Turdidae. ‘Sialia’ is derived from Greek and refers to a kind of bird, while ‘currucoides’ means ‘resembling Curruca’, a genus of Old World warblers.

Appearance

The mountain bluebird is a small songbird with a thin beak, sinewy dark legs, and a rounded head and belly. It is easy to tell the sexes apart by their appearance. The males exhibit bright blue upper feathers, fading to a pale white color toward the lower stomach. The females are gray, brown, and even pale orange. Most birds measure somewhere between 6 and 7 inches, roughly the size of a standard drinking glass.

Behavior

The mountain bluebird migrates farther than any other species of bluebird (and even more than many songbirds in general). Their breeding range extends as far north as Alaska, and their wintering range extends as far south as Mexico. They also appear all year round in California, Nevada, Utah, Colorado, New Mexico, and Arizona. Despite not being a social species, they appear to migrate in large flocks of up to 50 individuals, though much about their migratory behavior remains poorly understood.

These bluebirds have a set of (poorly studied) calls and songs to communicate important information such as alarm calls, all-clear signals, and territorial boundaries. Like many other songbirds, only the males are believed capable of communicating through true song, which probably has something to do with mating and breeding behavior. Song production may vary by region since some populations appear to sing more frequently than others.

Mountain bluebirds are also quite aggressive about maintaining and defending a set territory in the breeding season. They appear to dive-bomb and snap their bills at humans or any other threats that get too close to their nests. Besides their mate, they do not even tolerate other members of the same species in the breeding season.

Diet

The mountain bluebird has an omnivorous diet that depends on what is available at different times of year. When hunting for meat, they will sit on elevated perches to spot and then dive upon prey, or they’ll hover slightly off the ground and pounce.

What does the Mountain Bluebird eat?

The mountain bluebird will tend to feed upon seeds and fruits during the winter months, but the bulk of its diet actually consists of small invertebrates such as grasshoppers, caterpillars, crickets, spiders, cicadas, and much more. They play a vital environmental role by keeping insect populations in check.

Predators and Threats

Apart from predators, these birds face no other significant threats in the wild. Most of their range is sparsely inhabited and even protected by people. However, they do sometimes face fierce competition for nesting sites from other birds. This is exacerbated by the fact that nesting hollows may not always be available. They can also accidentally become trapped inside PVC pipes and other manmade structures.

What eats the mountain bluebird?

An adult mountain bluebird is preyed upon by Cooper’s hawks, peregrine falcons, great-horned owls, domesticated cats, and other species of hawks and falcons. Nests are also raided by raccoons, tree snakes, weasels, and rodents.

Reproduction, Babies, and Lifespan

As the breeding season approaches between the months of April and August, these birds establish short-term monogamous relationships lasting one or more breeding episodes. If the female produces a clutch early in the breeding season, then she is more likely to mate again with her partner for a second brood. This species is somewhat promiscuous, however, and has no particular compunction against mating with other birds besides its partner.

After the couple mates, the female will produce one egg per day until the nest contains four to eight eggs. Once the final egg is laid, the mother will incubate the eggs until they hatch about 12 to 16 days later, while the father provides her with food and care.

The offspring will usually hatch in the order in which they were originally laid. Since they are born completely helpless and defenseless, both parents play an important role in raising the young. After about three weeks, the chicks will gain their full flight feathers and a large degree of independence. But the first brood will sometimes stick around the nest to help their parents raise the next brood. Mortality rates are quite high among the young, but if they survive the juvenile phase, then the mountain bluebird will have a lifespan of six to 10 years.

Population

The IUCN Red List, which is a world-leading conservation tracker, currently classifies these birds as a species of least concern, so it requires no special conservation efforts. It is estimated that there are approximately six million mature individuals remaining in the wild. After a period of relative decline, the numbers appear to be increasing again.