I have gathered information about the Mountain Bluebirds in Washington, Idaho, Oregon, Montana, Wyoming, North Dakota, South Dakota, Alaska, British Columbia, Alberta, Saskatchewan, and Manitoba. I created an account for each state and Canadian Province including data on range occupied, migratory pattern, breeding activity and coexistence of the Mountain Bluebird with other species of bluebirds. Let’s dive and see what I have put together.
Mountain Bluebird Habitat
Mountain bluebirds use similar habitats across states and provinces in the northern part of its range. However, they show a slight variation in the winter and summer.
In general, the Mountain Bluebird lives in open terrain. They are relatively easy to find in the right habitat because they aren’t shy around people.
Look for them perched openly on things like treetops, fence posts, and power lines. They’re not hidden away.
Summer Habitat: In rural areas and ranches at higher elevations, you can often spot them while driving along rural roads. Just keep an eye on those perches mentioned earlier.
If you’re in a forested area, check out large openings, especially if there are aspen trees nearby. Aspen trees are important for providing nest cavities for Mountain Bluebirds in western mountain forests.
Winter Habitat: In winter, search for areas with juniper bushes that have lots of berries. Mountain Bluebirds often join other bird species like Western Bluebirds, American Robins, and Cedar Waxwings to feast on these berries.
Range occupied by the Mountain Bluebird before, during, and after the nesting season (left). Range occupied during the non-nesting season (right).
Mountain Bluebird in Washington
Range and Abundance
In the State of Washington, Mountain Bluebirds are found primarily on the eastern side of the Cascade Mountains and in certain other eastern regions of the state. They are rare on the west side of the Cascade crest.
The table below displays the approximate occupancy of Mountain Bluebirds of the State of Washington throughout the year. Percentages serve as an indirect measure of abundance.
| Seasons | Percentage of the State of Washington occupied by Mountain Bluebirds |
| Pre-breeding “migratory season”: 15 Feb-19 Apr | 29% |
| Breeding season: 26 Apr-31 Aug | 29% |
| Post-breeding “migratory season”: 7 Sep-30 Nov | 41% |
| Non-breeding season: 7 Dec-8 Feb | 0.6% |
Migratory patterns
In the State of Washington, the Mountain Bluebird is a migratory species. It is present in most of the state during the spring and summer but becomes rare or absent during the rest of the year. Some birds spend the winter around the Yahima Area.
- Pre-breeding “migratory season”: Birds begin to arrive in Washington State from the south approximately between February 15 through April 19 April.
- Post-breeding “migratory season”: After breeding juveniles and adults begin to move in all directions prior to heading south. This period occurs approximately between September 7 through November 30.
Breeding
Mountain Bluebirds primarily breed on the eastern side of the Cascade Mountains, which run through the central part of the state.
They also breed in the Okanogan Highlands and the Kettle and Selkirk Mountains to the northeast of the state.
In the east-central and southeastern part of Washington, Mountain Bluebirds breed in the Palouse Hills and the Blue Mountains.
- Breeding season: Mountain Bluebirds breed in Washington State during April 26 and August 31.
- Non-breeding season: Occurs between December 7 and February 8. During this period Mountain Bluebirds are rare, occurring only in part of the State.
Other Bluebirds in Washington State
The Western Bluebird (Sialia mexicana) overlaps with the Mountain Bluebird along the east side of the Cascade Mountains, in the Okanogan region and the north and southeast corners of the state.
Mountain Bluebirds in Idaho
Range and distribution
Mountain Bluebirds are found across most of Idaho, with a possible exception in the west-central border.
They are found at various elevations but are often seen more commonly at higher elevations, particularly at or above 1,500 meters.
The table below displays the approximate occupancy of Mountain Bluebirds of the State of Idaho throughout the year. Percentages serve as an indirect measure of abundance.
| Seasons | Percentage of the State of Idaho occupied by Mountain Bluebirds |
| Pre-breeding “migratory season”: 15 Feb-19 Apr | 72% |
| Breeding season: 26 Apr-31 Aug | 67% |
| Post-breeding “migratory season”: 7 Sep-30 Nov | 80% |
| Non-breeding season: 7 Dec-8 Feb | 10.4% |
Migratory patterns
In the State of Idaho, the Mountain Bluebird is highly migratory and it is present only during the spring and summer. A small population is year-round resident in the southwest corner of the State.
- Pre-breeding “migratory season” occurs approximately between February 15 through April 19 April.
- Post-breeding “migratory season” occurs approximately between September 7 through November 30.
Breeding
Mountain Bluebirds are mostly breeding visitors in Idaho. Pairs breed across most of the State except in the west-central border.
They breed at various elevations but more commonly at higher elevations, at or above 1,500 meters.
- Breeding season the peak of breeding activity occurs during April 26 and August 31.
- Non-breeding season: Occurs between December 7 and February 8. During this period Mountain Bluebirds are absent from most of the State of Idaho except for the southwest corner of the State where they are year-round residents.
Other Bluebirds in Idaho
During the spring and summer months the Mountain and Western Bluebirds overlap on the western half of Idaho.
Mountain Bluebirds in Oregon
Range and distribution
In Oregon State the Mountain Bluebird is found nearly exclusively on the east of the Cascade Mountains. This corresponds to the eastern two-thirds of the state.
The table below displays the approximate occupancy of Mountain Bluebirds of the State of Oregon throughout the year. Percentages serve as an indirect measure of abundance.
| Seasons | Percentage of the State of Montana occupied by Mountain Bluebirds |
| Pre-breeding “migratory season”: 15 Feb-19 Apr | 53% |
| Breeding season: 26 Apr-31 Aug | 47% |
| Post-breeding “migratory season”: 7 Sep-30 Nov | 57% |
| Non-breeding season: 7 Dec-8 Feb | 35% |
Migratory patterns
In the State of Oregon, the Mountain Bluebird is a year-round resident along the central part of the State, East of the Cascade Mountains.
The eastern third of Oregon is occupied by breeding birds during the spring and summer. Mountain Bluebirds leave this region during the winter, though a few individuals stay year-round.
- Pre-breeding “migratory season”: Birds begin to occupy the eastern third of Oregon approximately between February 15 through April 19 April.
- Post-breeding “migratory season”: After breeding juveniles and adults begin to move in all directions prior to leaving the eastern third of the State. This period occurs approximately between September 7 through November 30.
Breeding
In Oregon State the Mountain Bluebird is a breeding visitor in part of the state and permanent resident in others.. Therefore it breeds during the Spring and Summer on the east of the Cascade Mountains or the eastern two-thirds of the state.
- Breeding season: Mountain Bluebirds breed in Oregon during April 26 and August 31.
- Non-breeding season: Occurs between December 7 and February 8. During this period Mountain Bluebirds are absent from the eastern two-thirds of Oregon.
Other Bluebirds in Oregon
During the spring and summer months the Mountain and Western Bluebirds occupy the same areas. In some parts of Oregon, these two bluebirds can be found side by side.
Mountain Bluebirds in Montana
Range and distribution
Mountain Bluebirds are found in most of the State of Montana. They tend to be less common towards the eastern third of the state.
The table below displays the approximate occupancy of Mountain Bluebirds of the State of Montana throughout the year. Percentages serve as an indirect measure of abundance.
| Seasons | Percentage of the State of Montana occupied by Mountain Bluebirds |
| Pre-breeding “migratory season”: 15 Feb-19 Apr | 61% |
| Breeding season: 26 Apr-31 Aug | 59% |
| Post-breeding “migratory season”: 7 Sep-30 Nov | 70% |
| Non-breeding season: 7 Dec-8 Feb | 0% |
Migratory patterns
The Mountain Bluebird is a migratory bird in Montana, and its migration occurs in two phases.
- Pre-breeding “migratory season”: Birds begin to arrive in Montana from the south. It occurs approximately between February 15 through April 19 April.
- Post-breeding “migratory season”: After breeding juveniles and adults begin to move in all directions prior to heading south. This period occurs approximately between September 7 through November 30.
Breeding
The presence of Mountain Bluebirds in Montana is linked to both the breeding and non-breeding seasons.
- Breeding season: Mountain Bluebirds breed in Montana during April 26 and August 31. Including the pre and post breeding movements, birds are present in the state between February 15 through November 30.
- Non-breeding season: Occurs between December 7 and February 8. During this period Mountain Bluebirds are absent from the State of Montana.
Other Bluebirds in Montana
Two species of bluebirds occur in Montana: the Western and Mountain Bluebirds. Western Bluebirds are found in Northwest Montana during the spring and summer, and in this region, both species of bluebirds coexist.
Mountain Bluebirds in Wyoming
Range and distribution
Mountain Bluebirds are found all across Wyoming, but they are more common at higher elevations.
The table below displays the approximate occupancy of Mountain Bluebirds of the State of Wyoming throughout the year. Percentages serve as an indirect measure of abundance.
| Seasons | Percentage of the State of Wyoming occupied by Mountain Bluebirds |
| Pre-breeding “migratory season”: 15 Feb-19 Apr | 81% |
| Breeding season: 26 Apr-31 Aug | 74% |
| Post-breeding “migratory season”: 7 Sep-30 Nov | 96% |
| Non-breeding season: 7 Dec-8 Feb | 3% |
Migratory patterns
In the State of Wyoming, the Mountain Bluebird is highly migratory. It is present only during the spring and summer months. Only a few individuals remain scattered in Wyoming during the winter months.
- Pre-breeding “migratory season” occurs approximately between February 15 through April 19 April.
- Post-breeding “migratory season” occurs approximately between September 7 through November 30.
Breeding
The Mountain Bluebird is a breeding visitor and breeds all across the State. Breeding is more common at higher elevations where suitable nest cavities are more readily available.
- Breeding season in Wyoming occurs during April 26 and August 31. Including the pre and post breeding movements, birds are present in the state between February 15 through November 30.
- Non-breeding season: Occurs between December 7 and February 8. During this period Mountain Bluebirds are mostly absent from the State of Wyoming.
Other Bluebirds in Wyoming
The Mountain Bluebird is the only bluebird found in most of Wyoming during the Spring and summer months. The Western and Mountain bluebirds overlap in a small region of the South boundary of the State.
Mountain Bluebirds in North and South Dakota
Range and distribution
In North and South Dakota, Mountain Bluebirds are reported as common in the extreme western portion of the State, adjacent to Montana and Wyoming.
The table below displays the approximate occupancy of Mountain Bluebirds of the States of North Dakota and South Dakota throughout the year. Percentages serve as an indirect measure of abundance.
| Seasons | Percentage of the State of North and South Dakota occupied by Mountain Bluebirds |
| Pre-breeding “migratory season”: 15 Feb-19 Apr | North Dakota: 17% South Dakota: 12% |
| Breeding season: 26 Apr-31 Aug | North Dakota: 8% South Dakota: 6% |
| Post-breeding “migratory season”: 7 Sep-30 Nov | North Dakota: 8% South Dakota: 16% |
| Non-breeding season: 7 Dec-8 Feb | North Dakota: 0% South Dakota: 0% |
Migratory patterns
In the States of North and South Dakota, the Mountain Bluebird is highly migratory. It is present only during the spring and summer months. No Mountain Bluebird is found in Wyoming during the winter months.
- Pre-breeding “migratory season” occurs approximately between February 15 through April 19 April.
- Post-breeding “migratory season” occurs approximately between September 7 through November 30.
Breeding
In North and South Dakota, Mountain Bluebirds are reported as breeders in the extreme western portion of the State, adjacent to Montana and Wyoming. While additional nesting activity may occur further east of the known breeding area these nesting records go unnoticed due to the lack of observers in these remote areas.
- Breeding season in North and South Dakota occurs during April 26 and August 31. Including the pre and post breeding movements, birds are present in the state between February 15 through November 30.
- Non-breeding season: Occurs between December 7 and February 8. During this period Mountain Bluebirds are absent from North and South Dakota.
Other Bluebirds in North and South Dakota
The Eastern Bluebird occurs in North and South Dakota. However, both the Mountain and Eastern Bluebirds overlap only on the extreme western portion of these states only during the Spring and summer months.
Mountain Bluebird in Alaska
Range and distribution
In general, there is little information about where the Mountain Bluebird is found in Alaska.
Observations have been made in various places in central Alaska during the spring and summer. Its range extends into the western Yukon region.
They’ve been seen during spring and summer in places like Eagle, Tanacross, the Robertson River area, and Fairbanks.
Contrary to what one might expect, given the high latitude and harsh winters, the Mountain Bluebird appears to be present but rare throughout the year in Alaska.
Migratory patterns
The Mountain Bluebird is migratory in Alaska. There appears to be an influx of birds during the months of April and May. However, there is a lack of information regarding its arrival and departure times.
Breeding
- The Mountain Bluebird is a rare breeder in central Alaska.
- They have only been reported nesting in the central part of the state. However, there may be pairs breeding in other locations but are not reported due to the lack of observers.
Other Bluebirds in Alaska
The Mountain Bluebird is the only species of bluebird in the State.
Mountain Bluebirds in British Columbia, Alberta, Saskatchewan and Manitoba
Mountain bluebird distribution, breeding, and migratory patterns in the British Columbia, Alberta, Saskatchewan and Manitoba are similar. Hence, these Canadian provinces are treated in a single section.
Range and distribution
British Columbia: Mountain Bluebirds are most common in the southern part of British Columbia, but there is uncertainty about their population in the north and the middle of the province. There are scattered reports of them breeding in the far north, which might connect to populations in Yukon and Alaska, but this information needs confirmation.
The table below displays the approximate occupancy of Mountain Bluebirds of the Province of British Columbia throughout the year. Percentages serve as an indirect measure of abundance.
| Seasons | Percentage of British Columbia Province occupied by Mountain Bluebirds |
| Pre-breeding “migratory season”: 15 Feb-19 Apr | 16% |
| Breeding season: 26 Apr-31 Aug | 19% |
| Post-breeding “migratory season”: 7 Sep-30 Nov | 17% |
| Non-breeding season: 7 Dec-8 Feb | 0% |
Alberta: Mountain Bluebirds are common in the southern two-thirds of Alberta, especially in the foothills of the Rockies, central areas around Calgary and Edmonton, and specific areas in the south and southeast. However, there are fewer records in some parts due to nesting site limitations.
As with other Canadian Provinces, there’s uncertainty about their presence in the northeast part of the province.
The table below displays the approximate occupancy of Mountain Bluebirds of the Province of Alberta throughout the year. Percentages serve as an indirect measure of abundance.
| Seasons | Percentage of Alberta Province occupied by Mountain Bluebirds |
| Pre-breeding “migratory season”: 15 Feb-19 Apr | 11% |
| Breeding season: 26 Apr-31 Aug | 15% |
| Post-breeding “migratory season”: 7 Sep-30 Nov | 8% |
| Non-breeding season: 7 Dec-8 Feb | 0% |
Saskatchewan: Mountain Bluebirds are found in the lower half of Saskatchewan, with the majority of records in the trembling aspen parkland region.
They are also found along the southern border and have been seen in the northern part of the province, though their status in the north is uncertain.
The table below displays the approximate occupancy of Mountain Bluebirds of the Province of Saskatchewan throughout the year. Percentages serve as an indirect measure of abundance.
| Seasons | Percentage of Saskatchewan Province occupied by Mountain Bluebirds |
| Pre-breeding “migratory season”: 15 Feb-19 Apr | 18% |
| Breeding season: 26 Apr-31 Aug | 22% |
| Post-breeding “migratory season”: 7 Sep-30 Nov | 9% |
| Non-breeding season: 7 Dec-8 Feb | 0% |
Manitoba: Mountain Bluebirds can be regularly found in the aspen parkland region in the southwestern part of the province, below a line that stretches from the Saskatchewan border to the southern border of Manitoba.
The table below displays the approximate occupancy of Mountain Bluebirds of the Province of Manitoba throughout the year. Percentages serve as an indirect measure of abundance.
| Seasons | Percentage of the Province of Manitoba occupied by Mountain Bluebirds |
| Pre-breeding “migratory season”: 15 Feb-19 Apr | 1% |
| Breeding season: 26 Apr-31 Aug | 3% |
| Post-breeding “migratory season”: 7 Sep-30 Nov | 0% |
| Non-breeding season: 7 Dec-8 Feb | 0% |
Breeding in the Canadian Provinces
Mountain Bluebirds breed in most places where they are observed during the spring and summer. Nesting in the far north of these provinces is scattered and may be underestimated due largely to the lack of observers.
Migratory patterns
The Mountain Bluebird is a highly migratory bird in British Columbia, Alberta, Saskatchewan and Manitoba. These provinces constitute this bluebird’s breeding grounds and are present there exclusively to breed. The Mountain Bluebird migrates south during the non-breeding season.
Other Bluebirds in the region
The Mountain Bluebird is the only bluebird species in most of the Canadian Provinces.
It overlaps with the Western Bluebird in a small partition of Southeast British Columbia in Vancouver and both east and west sides of the Cascade Range in the Georgia Depression.
In conclusion, the comprehensive data collected about Mountain Bluebirds in Washington, Idaho, Oregon, Montana, Wyoming, North Dakota, South Dakota, Alaska, British Columbia, Alberta, Saskatchewan, and Manitoba shows a clear pattern of range occupancy related to Mountain Bluebird breeding activity. Mountain Bluebirds migrate and occupy these states and provinces from mid-February through November, retreating to the south and remaining absent from most of the northerly portion of their range during the months of December through mid-February.
The range of the Mountain Bluebird only overlaps with that of the Western and Eastern Bluebirds in a few small areas.
References:
- Johnson, L. S. and R. D. Dawson (2020). Mountain Bluebird (Sialia currucoides), version 1.0. In Birds of the World (P. G. Rodewald, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA.
- eBird Science.