Mountain Bluebird

Mountain Bluebird

Arctic bluebird, Mountain bluebird

Sialia currucoides
Population size
Life Span
6-9 years
g oz 
cm inch 
cm inch 

The mountain bluebird (Sialia currucoides ) is a small migratory thrush that is found in mountainous districts of western North America. It has a light underbelly and black eyes. Adult males have thin bills and are bright turquoise-blue and somewhat lighter underneath. Adult females have duller blue wings and tail, grey breast, grey crown, throat and back. In fresh fall plumage, the female's throat and breast are tinged with red-orange, brownish near the flank contrasting with white tail underparts. Their call is a thin 'few'; while their song is warbled high 'chur chur'. It is the state bird of Idaho and Nevada. It is an omnivore and it can live 6 to 10 years in the wild. It eats spiders, grasshoppers, flies and other insects, and small fruits. The mountain bluebird is a relative of the eastern and western bluebirds.


The Mountain bluebird, also known as the Arctic bluebird - is a small thrush that is easily identified by the vivid bright blue plumage of the male. In fact, this species has the bluest plumage out of all the North American bluebirds. The female is mainly gray but has a bluish tint, particularly on her wings and tail. She also has a white eye-ring, lacking in the male, and some females have a light reddish-brown color on their breasts and throats. Juveniles look like females but with slightly duller and darker upper parts, and a scaly effect, especially on their throat and breast.



These birds breed as far north as eastern and central Alaska, and south through central and western Canada (western Manitoba and southern Yukon) to areas in the west of the US (east of the Rockies). Mountain bluebirds can be found in some states year-round, however, some populations generally migrate south to Mexico in the winter and north into western Canada and even Alaska in the summer. Mountain bluebirds breed in grassland where there are scattered shrubs and thickets, tree-line tundra and clear-cuts, and prairie forest. They need cavities to nest in. They winter in flat grassland that features some trees and bushes, meadows with trees and hedges, lowland, farmland, and different types of forest.

Mountain Bluebird habitat map

Climate zones

Mountain Bluebird habitat map

Habits and Lifestyle

During the breeding season in spring and summer, Mountain bluebirds usually are seen alone, in pairs, or - at the end of the breeding season - in family groups of a few members. They are diurnal and forage from perches, as other bluebirds do, snatching food from the ground, from vegetation, and in mid-air. They are excellent foragers in the air, hovering kestrel-like before they drop onto their prey, or catch insects on the wing. Darting flight and hovering requires 8 to 4 times as much energy as does hunting from a perch, therefore they tend to use these methods when food is scarce. Apart from migration, Mountain bluebirds perform movements linked to the availability of fruit. The birds travel in flocks of as many as 30 individuals, sometimes more. During winter, they often form loose flocks with other species of passerine. The call of Mountain bluebirds is a thin 'few'; while their song is warbled high 'chur chur'.

Seasonal behavior
Bird's call

Diet and Nutrition

Mountain bluebirds are carnivores (insectivores) and herbivores (frugivores). During the summer, their diet consists of insects; while, in the winter months they eat mostly berries (like Juniper berries, Russian-olive berries, elderberry, etc.) and fruit seeds (such as mistletoe seeds and grapes, just to name a few).

Mating Habits

13-14 days
5.5-12 weeks
4-8 eggs

Mountain bluebirds form pair bonds which are monogamous. This means that males mate with only one female and females mate with only one male. At the start of the breeding season, males are the first to arrive at the breeding grounds. They select a nest site, being a cavity in a tree or a rock crevice. The females then arrive, and to attract a female, a male flies around the site of the nest while calling. April to September is the breeding season. This species generally produces two broods. The building of the nest is done by the female, sometimes with help from the male, which will guard her or bring some materials. 4-8 eggs of pale blue are laid and are incubated over 13-14 days. Both parents feed, strongly protect and defend the chicks. During this time they are often very aggressive. The young fledge at 18-21 days and depend on their parents for another 3 weeks to 2 months.


Population threats

Mountain bluebirds are quite common and they are not currently threatened. Their populations, however, are declining in places where trees are not big enough to provide natural cavities for nesting, and where agricultural and forestry practices have reduced the number of suitable nest sites. Competition is high for sites among cavity-nesting birds that can’t excavate them by themselves. Mountain, western, and eastern bluebirds compete for nesting boxes in places where their ranges overlap. European starlings, House sparrows, and House wrens are also fierce competitors with bluebirds for nest sites.

Population number

According to the IUCN Red List, the total population size of the Mountain bluebird is 6,000,000 mature individuals. Currently, this species is classified as Least Concern (LC) on the IUCN Red List and its numbers today are increasing.

Ecological niche

These small birds play an important role in the ecosystem they live in. Due to their insectivorous diet, they are helpful in controlling insect populations.

Fun Facts for Kids

  • The state bird of both Idaho and Nevada is the Mountain bluebird.
  • Robins are closely related to Mountain bluebirds.
  • Many native Americans of the southwest consider the Mountain bluebird to be a sacred symbol due to its azure-colored feathers. Navajo regard it as the image of a god, the herald of the rising sun.
  • A group of thrushes is known as a "mutation" or a "hermitage" of thrushes.
  • Female Mountain bluebirds pay more attention to a good nest site than to attractive males, choosing a mate purely according to the quality and location of the nesting cavity a male offers her - disregarding his attributes of singing, flying, or appearance.
  • The male frequently feeds the female while she is incubating or brooding. As her mate approaches with food, she may beg fledgling-style - her beak open, her wings quivering, and making begging calls. Often, she will wait until her mate is perching nearby, then will silently flick her wing farthest from him which usually sends the male off to find her some food.


1. Mountain Bluebird Wikipedia article -
2. Mountain Bluebird on The IUCN Red List -
3. Xeno-canto bird call -

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