Background information

Canadian Responsibility

We present Canadian responsibility scores for each species. We based the scores 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, we extracted Canadian and world population estimates from the 2019 Partners in Flight (PIF) Population Assessment Database (PIFa 2019 and PIFb 2019). For the few species without population estimates for Canada, we used the percent of the global breeding range in Canada, 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), quantitative criteria from COSEWIC, or expert opinion. For shorebirds, we extracted global population estimates from WPE5 (Wetlands International 2012), from Andres (2012), or the 2019 PIF Population Assessment DatabasePopulation Assessment Database (PIFb 2019) when appropriate, and Canadian population sizes were estimated based on the proportion of the range within Canada (Natureserve; Ridgely et al. 2007), or relative abundance data, when available. For waterfowl, we extracted Canadian estimates from the 2017 Population Status of Migratory Game Birds in Canada report (Canadian Wildlife Service Waterfowl Committee 2017), and obtained global population estimates from the North American Waterfowl Management Plan (NAWMP 2018). If estimates were not available for Canada, responsibility score were based on range maps or minimal population estimates. For seabirds, we derived the ratio of Canadian population estimates to range-wide estimates 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 Northern Gannets, BirdLife (2014); and for Pelagic Cormorant, because Delany and Scott (2006) provide only an estimate for North America, Hobson (2013). Note that some species are subject to taxonomic uncertainty and estimates of Canadian responsibility could be different if a different taxonomy were to be adopted. We sourced world population estimates for waterbirds mainly from Milko et al. (2003), as well as from the 2019 Partners in Flight (PIF) Population Assessment Database (PIFb 2019) when appropriate. ECCC experts reviewed the Canadian responsibility scores for each species and adjusted when necessary.

Categories used for Canadian responsibility scores are:

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
Non-native species that have been introduced to Canada are not assigned to a responsibility category


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