Rhinoceros Auklet
(Cerorhinca monocerata)


Picture of bird
© Andrew A Reding - License
For additional photos and vocalizations, visit Dendroica. (Link opens in a new window.)

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 to their nesting colonies 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.


Main designations for the species
DesignationStatusDateSubspecies, population
IUCN (Global)Least concern2018 
Wild Species (Canada)Apparently secure2015 
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
Canada700,000 - 800,000 breeding birds

Distribution maps


Migration strategy, occurrence

Short-distance migrant

Responsibility for conservation

Geographic areaResponsibility based on % of global population

Conservation and management

Predation from introduced raccoons has reduced counts of Rhinoceros Auklet at Helgesen and Saunders Islands in Haida Gwaii (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). The Rhinoceros Auklet is vulnerable to entanglement in gillnets in the waters off British Columbia. The declining population trend on Pine Island may be due, at least in part, to the relatively intense fishing effort in nearby waters (L. Wilson, ECCC, pers.comm.). The Rhinoceros Auklet is a sentinel species for marine contaminants trends in British Columbia (Elliott and Elliott 2013).


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