Western Bluebird
(Sialia mexicana)


Picture of bird
© Jukka Jantunen (flickr.com/photos/jukka_jantunen)
For additional photos and vocalizations, visit Dendroica. (Link opens in a new window.)

The Western Bluebird breeds in the dry montane forests of southern British Columbia and occasionally in the Rocky Mountains of Alberta; a portion of this population winters in Canada but many migrate to the western United States. This species is monitored by the Breeding Bird Survey and the Christmas Bird Count, both of which suggest that Western Bluebirds have shown large increases in population size since about 1970, despite the disappearance of small coastal populations (Campbell et al. 1997). A small population persists on southeastern Vancouver Island but continues to decline. This species has been identified as a priority for conservation and/or stewardship in one or more Bird Conservation Region Strategies in Canada.


Main designations for the species
DesignationStatusDateSubspecies, population
IUCN (Global)Least concern2018 
Wild Species (Canada)Apparently secure2015 
Bird Conservation Region StrategyPriority Species2013 

Population status

Geographic area or populationPopulation change relative to ~1970ReliabilityStatus in relation to goal
CanadaLarge IncreaseHighAt an Acceptable Level

Population estimate

Geographic area or populationPopulation estimate
Canada50,000 - 500,000 adults

Distribution maps


Migration strategy, occurrence

Short-distance migrant

Responsibility for conservation

Geographic areaResponsibility based on % of global population

General nesting period in Canada

Nesting period starts between mid-April and mid-May and ends in early August, depending on the region. Before or after this period, the probability of an active nest is lower.

Conservation and management

The Western Bluebird is a secondary cavity nester, traditionally using cavities excavated by woodpeckers such as the Northern Flicker (Guinan et al. 2008). It readily uses nest boxes, and large-scale nest box programs within its range in Canada have undoubtedly had a positive effect on its nesting success (Campbell et al. 1997, Guinan et al. 2008). Degradation of productive habitat is a concern throughout its range in North America. Open forests of pine, oak and Douglas-fir, which were formerly characterized by large trees in an open configuration, have become denser forests of younger trees as a result of logging and fire suppression (Guinan et al. 2008). Urbanization of the Western Bluebird's preferred Garry Oak habitat is also a primary issue for this species in southwestern British Columbia.


Bird conservation region strategies

Environment and Climate Change Canada and partners have developed Bird Conservation Region Strategies in each of Canada’s Bird Conservation Regions (BCRs). In these strategies, selected species are identified as priorities for one or more of the following reasons:

  • conservation concerns (i.e., species vulnerable due to population size, distribution, population trend, abundance, or threats)
  • stewardship responsibilities (i.e., species that typify the regional avifauna or have a large proportion of their range or population in the sub-region)
  • management concerns (i.e., species that require ongoing management because of their socio-economic importance as game species, or because of their impacts on other species or habitats)
  • other concerns (i.e., species deemed a priority by regional experts for other reasons than those listed above or because they are listed as species at risk or concern at the provincial level)

Select any of the sub-regions below to view the BCR strategy for additional details.

BCRs, marine biogeographic units, and sub-regions in which the species is listed as a priority
RegionSub-region and priority type
Northern Pacific RainforestNorthern Pacific Rainforest, sub-region and priority type: Pacific and Yukon -- Conservation