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Canada Jay or Blue Jay
Which jay is more common?
Ron
Pittaway
First
published in Toronto Ornithological Club Newsletter, September 2019,
No 289 |
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Blue Jay versus Canada Jay. Photo by Jean Iron |
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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. |
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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. |
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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. |
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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. |
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References
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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. |
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Partners in Flight Landbird
Conservation Plan 2016. Canadian Wildlife Service and United States
Fish and Wildlife Service.
https://www.partnersinflight.org/resources/the-plan/ |
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Strickland, D. and H.R. Ouellet. 2018. Canada
Jay. Birds of North America. Published online by Cornell Lab
of Ornithology, Ithaca, New York. |
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