Rhinoceros Auklet
(Cerorhinca monocerata)


Picture of bird
© Andrew A Reding - License
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Rhinoceros Auklets breed in colonies on offshore islands of the temperate North Pacific. Because they visit their colonies primarily at night and nest in deep burrows, it is difficult to monitor their abundance. Counts of occupied burrows suggest that the population's abundance has changed little relative to about 1970. However, disruptions in marine food webs and predator introductions have affected reproduction and survival. Rhinoceros Auklets are highly susceptible to mortality from entanglement in commercial gillnets. This species has been identified as a priority for conservation and/or stewardship in one or more Bird Conservation Region Strategies in Canada.


Listing of the main designations for the species
DesignationStatusDateSubspecies, population
IUCN (Global)Least Concern2012 
Wildspecies (Canada)Secure2010 
Bird Conservation Region StrategyPriority Species2013 

Population status

Geographic areaStatusReliability
CanadaLittle ChangeMedium

Population estimate

Canada700,000 - 800,000 breeding birds

Distribution maps


Migration strategy, occurrence

Short-distance migrant

Responsibility for conservation of world population


Conservation and management

Predation from introduced raccoons has reduced counts at Helgesen and Saunders Islands in the Queen Charlotte Islands (Gaston and Dechesne 1996), but abundance in this region is generally increasing otherwise. Also, variability in reproductive success is related to disruptions in the marine food web (Gaston et al. 2009). Specifically, spring phytoplankton concentrations and subsequent recruitment of Pacific sandlance, Ammodytes hexapterus, an important component of the diet fed to nestlings, appear to be strong predictors of auklet breeding success, and vary among years in response to changing wind patterns (Borstad et al. 2011).


Bird Conservation Region Strategies

Environment 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 either because of conservation concerns (i.e., those species vulnerable due to population size, distribution, population trend, abundance, or threats) or because of stewardship responsibilities (i.e., those species that typify the regional avifauna or have a large proportion of their range or population in the sub-region). Select any of the sub-regions below to view the BCR strategy for that region.

Listing of bird conservation regions, marine biogeographic units and sub-regions
Bird conservation region, marine biogeographic unitSub-region
Northern Pacific RainforestNorthern Pacific Rainforest, sub-region: Pacific and Yukon Region


  • Borstad, G., W. Crawford, J.M. Hipfner, R. Thompson and K.D. Hyatt. 2011. Enviromental control of the breeding success of rhinoceros auklets at Triangle Island, British Columbia. Marine Ecology Progress Series 424:285-302.
  • Gaston, A.J. and S.B. Dechesne. 1996. Rhinoceros Auklet (Cerorhinca monocerata). The Birds of North America Online (A. Poole, Ed.). Cornell Lab of Ornithology, Ithaca, New York. Gaston, A.J. and S.B. Dechesne. 1996. Rhinoceros Auklet (Cerorhinca monocerata). The Birds of North America Online (A. Poole, Ed.). Cornell Lab of Ornithology, Ithaca, New York. (Link)
  • Gaston, A.J., D.F. Bertram, A.W. Boyne, J.W. Chardine, G. Davoren, A.W. Diamond, A. Hedd, W.A. Montevecchi, J.M. Hipfner, M.J.F. Lemon, M.L. Mallory, J.-F. Rail and G.J. Robertson. 2009. Changes in Canadian seabird populations and ecology since 1970 in relation to changes in oceanography and food webs. Environmental Reviews 17:267-286.