Canada Warbler
(Cardellina canadensis)

Summary

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

Still fairly abundant and widespread, the Breeding Bird Survey indicates this primarily Canadian-breeding species has undergone a significant long-term, decrease since about 1970. That decrease, which led to its listing under the Species at Risk Act in 2010, is thought to be due primarily to limitations on the wintering grounds (Wilson et al. 2018). This species has been identified as a priority for conservation and/or stewardship in one or more Bird Conservation Region Strategies in Canada.

Designations

Main designations for the species
DesignationStatusDateSubspecies, population
COSEWIC (Canada)Threatened2008 
SARA (Canada)Threatened2010 
IUCN (Global)Least concern2018 
Partners in Flight (North America)Watch list - yellow D2017 
Wild Species (Canada)Vulnerable2015 
State of North America’s BirdsWatch list2016 
Bird Conservation Region StrategyPriority Species2013 

Population status

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

Population estimate

Geographic area or populationPopulation estimate
Canada1,000,000 - 5,000,000 adults
 

Distribution maps

 

Migration strategy, occurrence

Long-distance migrant

Responsibility for conservation

Geographic areaResponsibility based on % of global population
CanadaHigh

General nesting period in Canada

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

Conservation and management

Loss of wintering habitat in South America is likely one of the most important factors responsible for the decline of the Canad Warbler (Wilson et al. 2018), as well as loss and degradation of habitat on the breeding grounds (e.g., loss of understory, conversion of eastern forested swamps; Reitsma et al. 2010). More recently, there is a suggestion that declines in Canada Warbler may be related to spruce budworm populations (Sleep et al. 2009), which have been in decline since the mid-1980s. Spruce budworm populations are known to be cyclical (Royama 1984) and can be expected to surge again to high levels in the near future (Royama et al. 2005). However, other studies suggest there is little evidence at the local scale that Canada Warbler responds strongly to budworm infestation (Venier and Holmes 2010). The species is also highly vulnerable to collisions with buildings and vehicles (Environment Canada 2016b). The Canada Warbler International Conservation Initiative, a public-private partnership, was launched in 2013 to further investigate the causes of population declines and coordinate conservation efforts throughout the species' range. For information on the legal status of this species under the Species at Risk Act (SARA) and to view available recovery documents, see the SARA Registry.

 

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
Atlantic Northern ForestsAtlantic Northern Forests, sub-region and priority type: Atlantic, NB -- Conservation & Stewardship
Atlantic Northern ForestsAtlantic Northern Forests, sub-region and priority type: Atlantic, NS -- Stewardship
Atlantic Northern ForestsAtlantic Northern Forests, sub-region and priority type: Atlantic, PE -- Other
Atlantic Northern ForestsAtlantic Northern Forests, sub-region and priority type: Quebec -- Conservation & Stewardship
Boreal Hardwood TransitionBoreal Hardwood Transition, sub-region and priority type: Ontario and Manitoba -- Conservation & Stewardship
Boreal Hardwood TransitionBoreal Hardwood Transition, sub-region and priority type: Quebec -- Conservation & Stewardship
Boreal Softwood ShieldBoreal Softwood Shield, sub-region and priority type: Ontario -- Conservation & Stewardship
Boreal Softwood ShieldBoreal Softwood Shield, sub-region and priority type: Prairie and Northern -- Other
Boreal Softwood ShieldBoreal Softwood Shield, sub-region and priority type: Quebec -- Stewardship
Boreal Taiga PlainsBoreal Taiga Plains, sub-region and priority type: Prairie and Northern -- Other
Lower Great Lakes/St. Lawrence PlainLower Great Lakes/St. Lawrence Plain, sub-region and priority type: Ontario -- Conservation
Lower Great Lakes/St. Lawrence PlainLower Great Lakes/St. Lawrence Plain, sub-region and priority type: Quebec -- Conservation
Taiga Shield and Hudson PlainsTaiga Shield and Hudson Plains, sub-region and priority type: Ontario -- Conservation
 

References