Blue-gray Gnatcatcher
(Polioptila caerulea)


Picture of bird
© John Reaume
For additional photos and vocalizations, visit Dendroica. (Link opens in a new window.)

Primarily a species of the southwestern and eastern United States, the small population of the Blue-gray Gnatcatcher in Canada is found mainly in southern Ontario and in a few areas in southern Québec. Results from the Breeding Bird Survey suggest that this species' population has shown a large increase since about 1970. The Atlas of the Breeding Birds of Ontario suggests that the Blue-gray Gnatcatcher's range has expanded northward. This population increase and northward range expansion may be related to warming temperatures as a result of global climate change, and re-forestation of former agricultural areas (McCracken 2007).


Main designations for the species
DesignationStatusDateSubspecies, population
IUCN (Global)Least concern2018 
Wild Species (Canada)Apparently secure2015 

Population status

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

Population estimate

Geographic area or populationPopulation estimate
Canada5,000 - 50,000 adults

Distribution maps


Migration strategy, occurrence

Long-distance migrant

Responsibility for conservation

Geographic areaResponsibility based on % of global population
CanadaVery Low

General nesting period in Canada

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

Conservation and management

A species that winters primarily in scrubland habitat, it is unlikely that tropical deforestation will have a large negative influence on wintering populations (Kershner and Ellison 2012). Possibly affected by Brown-headed Cowbird parasitism, evidence of cowbird control has been found effective as a last resort management strategy (Kershner and Ellison 2012). With only a small portion of the North American population in Canada and increasing numbers, there are few conservation concerns for this species in Canada.


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