Parasitic Jaeger
(Stercorarius parasiticus)


Picture of bird
© Charles M. Francis, CWS
For additional photos and vocalizations, visit Dendroica. (Link opens in a new window.)

Parasitic Jaegers breed across the Canadian Arctic and winter at sea. Off the west coast of Canada, Parasitic Jaegers occur in both nearshore and offshore waters in low numbers, primarily between May and October (Kenyon et al. 2009), although they have been observed rarely, in April and in late December (Campbell et al. 1990). Their widely dispersed population is difficult to monitor, so their status in Canada relative to about 1970 remains unknown. Parasitic Jaegers prey on the eggs of other birds, so changes in the population status of their prey species could potentially affect their numbers. 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)Secure2015 
Bird Conservation Region StrategyPriority Species2013 

Population status

Geographic area or populationPopulation change relative to ~1970ReliabilityStatus in relation to goal
CanadaData DeficientData DeficientData Deficient

Population estimate

Geographic area or populationPopulation estimate
Canada100,000 - 200,000 breeding birds

Distribution maps


Migration strategy, occurrence

Long-distance migrant

Responsibility for conservation

Geographic areaResponsibility based on % of global population

Conservation and management

In comparison to Canada's other two jaeger species, Parasitic Jaegers are less specialised on lemmings and prey more on the eggs and chicks of other birds (Wiley and Lee 1999). They frequently breed near colonies of other birds such as Ross' or Snow Geese, and the dramatic increases in the abundance of these species in some regions could positively affect jaeger populations. Lack of systematic monitoring information, however, precludes a test of this hypothesis.


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
Taiga Shield and Hudson PlainsTaiga Shield and Hudson Plains, sub-region and priority type: Ontario -- Conservation