Canada Jay or Blue Jay

Which jay is more common?

Ron Pittaway

First published in Toronto Ornithological Club Newsletter, September 2019, No 289

Blue Jay versus Canada Jay. Photo by Jean Iron


The decline of Canada Jays in Algonquin Park made me wonder about its total population in Ontario. Then I wondered about the number of Blue Jays. I assumed that Blue Jays would be more common than Canada Jays. This assumption was based on many years of seeing thousands of Blue Jays migrating south in fall along the shoreline of Lake Ontario in Toronto. By comparison, my lifetime total of Canada Jays seen in Ontario is less than 500 individuals even though I lived in its range for many years.


Which jay is more common in Ontario? The second Atlas of Breeding Birds of Ontario 2001-2005 (Cadman et al. 2007) gives population estimates for many birds in the province. These density estimates are based on point counts. The atlas estimates are 5,000,000 Canada Jays and 700,000 Blue Jays in Ontario. That Canada Jays outnumbered Blue Jays by a ratio of 7 to 1 surprised me until I thought about the vast expanse of boreal forest in Ontario.


Which jay is more common in North America? Strickland and Ouellet (2018) used data from the Breeding Bird Survey to estimate a Canada Jay population of 26,000,000 in North America. A Blue Jay population of 17,000,000 in North America is reported in the Partners in Flight Landbird Conservation Plan 2016, making it the second most common jay in North America. The Canada Jay is the most abundant of the 11 species of jays in North America and it has the largest breeding range.


Acknowledgments: Denys Gardiner reminded me that population estimates for Canada Jay and Blue Jay were published in the second Ontario atlas. I thank Michel Gosselin for information and comments and Jean Iron for comments and photo.



Cadman M.D. and D.A. Sutherland, G.G. Beck, D. Lepage, A.R. Couturier. 2007. Atlas of Breeding Birds of Ontario 2001-2005. Bird Studies Canada, Environment Canada, Ontario Field Ornithologists, Ontario Ministry of Natural Resources, Ontario Nature. xxii + 706 pages.


Partners in Flight Landbird Conservation Plan 2016. Canadian Wildlife Service and United States Fish and Wildlife Service.


Strickland, D. and H.R. Ouellet. 2018. Canada Jay. Birds of North America. Published online by Cornell Lab of Ornithology, Ithaca, New York.