Population status

Rhinoceros Auklet
(Cerorhinca monocerata)

The most reliable population data for Rhinoceros Auklet in Canada is from Environment Canada's Seabird Colony Counts (primarily counts of occupied burrows in fixed plots at breeding colonies). These indices of population size are available for four important colonies in the species' Pacific range. At three of the four colonies, counts indicate slight to moderate increases in population abundance since 1984, while at the fourth, counts indicate a slight decrease. Dramatic declines in counts at two additional colonies are the result of predator introductions; because these trends reflect this local conservation issue, they are less likely to reflect the population's national status. The Canadian population has likely changed little or has increased slightly relative to about 1970, but systematic monitoring information prior to 1984 is lacking. Consequently, the assessment of status is considered to only have moderate reliability.

 

Analysis of Seabird Colony Counts

Additional information on: Analysis of Seabird Colony Counts

Population trends by geographic area
Geographic areaTime PeriodAnnual trend (%)Table 1 - footnote 1Limits
LowerUpper
Lucy Island, British Columbia1984-20080.3-1.62.5
Pine Island, British Columbia1984-2006-1.0-1.73.0
Skaang Gwai, British Columbia1985-20061.7  
Triangle Island, British Columbia1984-20090.6-0.72.3
Table 1 - Footnote 1

Annual trend measures changes in relative abundance

Return to table 1 - footnote 1 referrer

References

  • 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.