Background information

Canadian Responsibility

Canadian responsibility scores are presented for each species. Scores were based on the percent of the world population of the species estimated to be in Canada using the ratio of Canadian population estimates to range-wide estimates. For landbirds, Canadian and world population estimates were extracted from the 2012 Partners in Flight (PIF) Population Assessment Database. For the few species without population estimates for Canada, the percent of the global breeding range in Canada was used, based on NatureServe digital range maps for the Western Hemisphere (Ridgely et al. 2007), PIF estimates of proportion of range outside of the Western Hemisphere (Blancher et al. 2007), COSEWIC or expert opinion. For shorebirds, global population estimates were extracted from WPE5 (Wetlands International 2012), and Canadian population sizes were estimated on the basis of the proportion of the range within Canada (Natureserve: Ridgely et al. 2007), or relative abundance data, where available. For seabirds, the ratio of Canadian population estimates to range-wide estimates was derived from the following sources: for loons, gulls, terns and cormorants, Delany and Scott (2006); for auks, Gaston and Jones (1998); for petrels, Brooke (2004); for gannets, BirdLife (2012); and for Pelagic Cormorant, because Delany and Scott (2006) provide only an estimate for North America, Hobson (1997). Note that some seabird species are subject to taxonomic uncertainty and estimates of Canadian responsibility could be different if a different taxonomy was adopted. World population estimates for water birds were taken mainly from Milko et al. (2003). The Canadian responsibility scores for each species were reviewed by Environment Canada staff and adjusted as necessary.

Categories for responsibility are as follows:

Very High
> 80% of world population estimated to be in Canada
50 to 80% in Canada
20 to 50% in Canada
1 to 20% in Canada
Very Low
< 1% in Canada
Not applicable
Alien species that have been introduced to Canada are not assigned to a responsibility category


  • BirdLife International. 2012. BirdLife International. 2014. Species factsheet: Morus bassanus. The IUCN Red List of Threatened Species. Version 2014.3.
  • Blancher, P.J., K.V. Rosenberg, A.O. Panjabi, B. Altman, J. Bart, C.J. Beardmore, G.S. Butcher, D. Demarest, R. Dettmers, E.H. Dunn, W. Easton, W.C. Hunter, E.E. Iñigo-Elias, D.N. Pashley, C.J. Ralph, T.D. Rich, C.M. Rustay, J.M. Ruth, and T.C. Will. 2007. Guide to the Partners in Flight Population Estimates Database. Version: North American Landbird Conservation Plan 2004. Partners in Flight Technical Series No 5.
  • Brooke, M. 2004. Albatrosses and Petrels Across the World. Oxford University Press, Oxford, UK. 518 pp.
  • Delany, S. and D. Scott. 2006. Waterbird Population Estimates, Fourth Edition. Wetlands International, Wageningen, The Netherlands. 8 pp.
  • Gaston, A.J. and I.L. Jones. 1998. The auks, Alcidae. Oxford University Press, Oxford, UK. 232 pp.
  • Hobson, K.A. 1997. Pelagic Cormorant (Phalacrocorax pelagicus), The Birds of North America Online (A. Poole, Ed.). Cornell Lab of Ornithology, Ithaca, New York.
  • Milko, R., L. Dickson, R. Elliot and G. Donaldson. 2003. Wings Over Water: Canada’s Waterbird Conservation Plan. Canadian Wildlife Service, Environment Canada, Ottawa, ON. 28 pp.
  • Ridgely, R. S., T. F. Allnutt, T. Brooks, D. K. McNicol, D. W. Mehlman, B. E. Young, and J. R. Zook. 2007. Digital Distribution Maps of the Birds of the Western Hemisphere, version 3.0. NatureServe, Arlington, Virginia, USA.