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Mountain Bluebird
Thrushes · Short-distance migrant

Mountain Bluebird

Arctic Bluebird · Sialia currucoides

Least Concern15–18 cm · 24–37 g

By the Birdfact teamChecked byNathan Cope

A flash of sky-blue streaking across the western mountains signals one of North America's most eye-catching songbirds at work, hovering like a kestrel before diving for insects in the alpine meadows.
On this page13 sections
  1. How to recognise it
  2. Its size
  3. Its song and calls
  4. When and where to see it
  5. What it eats
  6. Nesting and breeding
  7. Behaviour
  8. Conservation
  9. Similar birds
  10. More photos
  11. Mountain Bluebird guides
  12. Quick facts
  13. Sources

How to recognise it

The Mountain Bluebird is a small thrush with a slender profile and long wings. Males are a rich, bright blue across their upperparts, fading to lighter blue on the breast and white on the lower belly. The wing tips are dusky, not pure blue.

Females are primarily grey-brown, with a distinctive blue rump patch and blue in the wings and tail. Their underparts can range from grey-brown to pale buff, with a whiter chin and belly. They also have a subtle white eye ring.

Young birds look similar to females but are darker, with distinctive white spotting on their breast and upper flanks.

Its size

Adults
Length
15–18 cm
Wingspan
28–36 cm
Weight
24–37 g

Its song and calls

The Mountain Bluebird's song is a series of soft, warbling phrases, often described as 'few-few-few' or 'chur-chur'. Their call is a thin, musical 'few' or 'phew'.

During courtship, males sing more frequently, producing longer, more varied songs to attract mates.

When and where to see it

North America

OctoberIn season

Arriving in 2 placesLast month in 6 places

Most recorded in October

  1. 1. Wyoming0.65%
  2. 2. Colorado0.63%
  3. 3. New Mexico0.43%
  4. 4. Utah0.43%
  5. 5. South Dakota0.27%

Each dot is a county, state or province: the bigger and darker, the larger the bird’s share of that place’s bird records that month. Grey dots: no regular records. The ringed point is the centre of the bird’s records this month; the arrow shows how it moved since last month, and the dashed loop its path through the year. “Arrivals” colours places where it becomes regular this month (orange) or is in its last regular month (grey). GBIF eBird Observation Dataset, 2019–2024. Map data: Natural Earth, US Census Bureau; place centres © OpenStreetMap contributors.

In your area

See when the Mountain Bluebird is recorded in your county, state or province.

or

How often the Mountain Bluebird turns up in the United States and Canada through the year, from birdwatchers' records.

United States

Resident · all year · most records in June

Canada

Summer visitor · all year · most records in April

Regularly recordedOccasionalBar height: share of all bird records that month
Show as a table
MonthUnited StatesCanada
January0.034% (regular)0.013% (regular)
February0.026% (regular)0.006% (regular)
March0.045% (regular)0.055% (regular)
April0.037% (regular)0.074% (regular)
May0.033% (regular)0.038% (regular)
June0.074% (regular)0.064% (regular)
July0.066% (regular)0.039% (regular)
August0.042% (regular)0.019% (regular)
September0.039% (regular)0.022% (regular)
October0.036% (regular)0.012% (regular)
November0.027% (regular)0.009% (regular)
December0.029% (regular)0.008% (regular)

Worldwide: recorded regularly in 3 countries

Countries where it was recorded in at least 3 of the 6 years 2019–2024. Linked countries have their own bird list.

North America (3)

Tips for seeing it

  • Look for Mountain Bluebirds in open, high-elevation areas with scattered trees.
  • Listen for their soft, warbling song, especially during spring.
  • Observe fenceposts and low perches in grasslands for hunting birds.
  • In winter, search for flocks in lower elevation open areas.
  • In the western United States, check bluebird nest boxes in appropriate habitats.

What it eats

Mountain Bluebirds primarily feed on insects, including grasshoppers, caterpillars, and beetles. They supplement their diet with small fruits and berries, especially during winter months when insects are scarce.

Their hunting style involves hovering and dropping to the ground to catch prey.

Nesting and breeding

Mountain Bluebirds form monogamous pairs during the breeding season, which typically begins in late spring. Males perform aerial displays and offer nesting material to attract females.

Nests are built in natural tree cavities, old woodpecker holes, or nest boxes. Females construct the nest using grasses and fine plant materials, laying 4-8 pale blue eggs.

Incubation lasts about 13 days, primarily done by the female. Both parents feed the nestlings, which fledge after 18-21 days. Pairs often raise two broods per season in favorable conditions.

Behaviour

Mountain Bluebirds are often seen perched on fenceposts or low branches, scanning the ground for insects. They employ a distinctive 'drop and hover' hunting technique, flying down to catch prey on the ground or in mid-air.

During the breeding season, males perform aerial displays to attract mates, showcasing their vibrant plumage.

Conservation

While currently listed as Least Concern, Mountain Bluebirds face threats from habitat loss due to urban development and changes in agricultural practices.

Conservation efforts include the installation of nest boxes in suitable habitats, which has helped stabilize populations in some areas.

Similar birds

Often mistaken for

More photos

10 photos

Mountain Bluebird guides

1 guides

Quick facts

Length
15–18 cm
Wingspan
28–36 cm
Weight
24–37 g
Lifespan
4–6 years · oldest recorded 9 years
Family
Thrushes
Migration
Short-distance migrant
Global status (IUCN)
Least Concern
World population
5,600,000 mature individuals
Population trend
Increasing
Also called
Arctic Bluebird
Scientific name
Sialia currucoides

Sources

4
  1. 1BirdLife International. 2019. Sialia currucoides. The IUCN Red List of Threatened Species 2019: e.T22708556A137560639. Source (opens in a new tab)
  2. 2Sauer et al. (2017)
  3. 3Partners in Flight (2022) Source (opens in a new tab)
  4. 4Historical Longevity Records of North American Birds Source (opens in a new tab)
Spotted a mistake?Tell usHow we write and checkBy the Birdfact team · Updated

Checked by

Nathan Cope, founder and editor

Nathan founded Birdfact and leads its writers and contributors in the UK, the US and Canada. He has watched and studied birds for more than ten years, and checks every article and species guide before it’s published.

How we write and checkAbout Nathan