Cassin's Auklet
(Ptychoramphus aleuticus)


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

The Cassin’s Auklet is a small seabird that nests in shallow burrows and rock crevices on islands off the coast of British Columbia. Monitoring at several large breeding colonies suggest that the population has varied over time but overall has exhibited little change in abundance since about 1970. This species feeds primarily on zooplankton, so large-scale, long-term changes in the availability of its prey due to ocean warming and shifts in ocean currents may have contributed to the previously detected declines. In 2014, the Committee on the Status of Endangered Wildlife in Canada assessed the species as Special Concern, primarily based on the fact that British Columbia is home to 75-80% of the world’s breeding population, the threat of introduced mammalian predators into breeding colonies, and the potential of changing food availability due to climate change (COSEWIC 2014f). The species has not yet been listed under the Species at Risk Act. 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
COSEWIC (Canada)Special Concern2014 
SARA (Canada)No Status  
IUCN (Global)Near threatened2018 
Wild Species (Canada)Vulnerable2015 
Bird Conservation Region StrategyPriority Species2013 

Population status

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

Population estimate

Geographic area or populationPopulation estimate
Canada2,000,000 - 3,000,000 breeding birds

Distribution maps


Migration strategy, occurrence

Short-distance migrant

Responsibility for conservation

Geographic areaResponsibility based on % of global population

Conservation and management

The reproductive success of the Cassin’s Auklet is tied to the abundance and availability of their invertebrate prey (Hipfner 2008). Ocean warming, especially within the California Current, has affected prey abundance leading to reduced breeding conditions (Gaston et al. 2009). Recent studies have shown pronounced effects of extreme climate events on both adult survival and reproduction (Morrison et al. 2011). Similar to other burrow-nesting seabirds in the Pacific, the introduction of mammalian predators, such as rats and raccoons, to some nesting islands have also caused pronounced declines (Hipfner et al. 2010). Ongoing control of these introduced predators is necessary to protect Cassin’s Auklets and other seabirds (COSEWIC 2014f).


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 -- Stewardship