Double-crested Cormorant
(Phalacrocorax auritus)

Summary

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

The Double-crested Cormorant is the most abundant cormorant in Canada, and typically breeds on islands in both freshwater and marine environments. A variety of surveys provide strong evidence that Double-crested Cormorants have shown a large increase in abundance in Canada since the 1970s, and in some locations, these increases have been dramatic and accompanied by the establishment of new breeding colonies. 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)Not at Risk1978 
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
CanadaLarge IncreaseHighAt an Acceptable Level
 

Population estimate

Geographic area or populationPopulation estimate
Canada400,000 - 500,000 breeding birds
 

Distribution maps

 

Migration strategy, occurrence

Short-distance migrant

Responsibility for conservation

Geographic areaResponsibility based on % of global population
CanadaModerate

General nesting period in Canada

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

Conservation and management

Seen as a competitor by the fishing industry or an easily exploitable resource, the Double-crested Cormorant has long been vilified and persecuted at each of its life stages (Dorr et al. 2014). Its numbers were dramatically reduced in the 19th century as a result of direct persecution, and again in the 1960s and 1970s because of its susceptibility to contaminants such as DDT (Dorr et al. 2014). With the population’s recovery following the banning of DDT and tighter environmental regulations, conflicts began to arise in the name of competition with sport- and commercial-fishers, habitat degradation, and adverse impacts on other breeding birds. Though those impacts were often unsubstantiated, cormorant control was employed on both sides of the border (Wires 2015). Between 1998 and 2016, to protect public resources and commercial interests, the United States allowed cormorant control without requiring a permit (e.g., at aquaculture facilities). Since conflicts with humans will likely continue, and Double-crested Cormorant management will remain on the horizon, management methods, options, and policies need to be developed (Wires and Weseloh 2018).

 

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: Quebec -- Other
Great BasinGreat Basin, sub-region and priority type: Pacific and Yukon -- Other
Lower Great Lakes/St. Lawrence PlainLower Great Lakes/St. Lawrence Plain, sub-region and priority type: Ontario -- Conservation & Management
Northern Pacific RainforestNorthern Pacific Rainforest, sub-region and priority type: Pacific and Yukon -- Other
Northern RockiesNorthern Rockies, sub-region and priority type: Pacific and Yukon -- Other
 

References