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Another one of northern Minnesota’s iconic wildlife species appears to be in trouble, a likely victim of a changing climate. Area Christmas bird counts around the region have confirmed an …
Another one of northern Minnesota’s iconic wildlife species appears to be in trouble, a likely victim of a changing climate. Area Christmas bird counts around the region have confirmed an increasingly apparent trend of declining populations of gray jays, recently renamed officially to Canada jays. It’s a trend that researchers in parts of Canada have confirmed as well.
Research at Ontario’s Algonquin Provincial Park strongly suggests that milder autumns, with frequent freeze and thaw cycles, are having a particular impact on the Canada jay’s ability to successfully cache food supplies.
While many bird species are known to cache food, the behavior is particularly important to the survival of Canada jays, which live primarily in cold boreal forests where food is scarce in winter. The birds rely on cached food, which they gather and cache in the fall, to not only survive the winter but also as a primary food source for their nesting young. Canada jays nest much earlier than most other birds, often when there is still snow on the ground and when food sources that most other birds use to raise their young— such as insects— are not available.
In a 2021 study in the journal Global Change Biology (https://onlinelibrary.wiley.com/doi/epdf/10.1111/gcb.15445), a team of researchers have correlated a long-term decline in the Canada jay population in Algonquin Provincial Park with more frequent freeze-thaw cycles in the fall, which accelerates the deterioration of the caches that Canada jays distribute throughout their territories during that time period.
As the Timberjay has previously reported, temperatures in September and October in northeastern Minnesota have warmed more quickly in recent decades than other times of the year, and that may be a contributing factor to the apparent decline of Canada jays.
“Gray jays are a bellwether species for winter-related climate disruption because the food caches that they rely on to raise young in late winter rot if temperatures are too high,” notes Steve Wilson, a longtime bird researcher who lives in Tower and Isabella. Wilson, who has coordinated the Isabella Christmas bird count for 40 years, stated in a recent post-count wrap-up that the Canada jay numbers in their Jan. 1 bird count were at a 40-year low. The Isabella count had previously set the North American record for the most Canada jays on a count, with 154. This year, however, counters in Isabella found just 19.
Other area counts found similar low numbers of Canada jays. At the same time, the blue jay population appears to be on the rise, and that could be contributing to the decline in the number of Canada jays. Julie Grahn, who coordinates the Cook area Christmas bird count, said she’s noticed that blue jays in her yard appear to follow Canada jays at times, and postulates that they may have learned to rob their caches.
Blue jays also cache food, but they do it differently than Canada jays and aren’t as dependent on their wintertime caches as their more northerly cousins. Canada jay caches are somewhat unique among birds. They’re essentially little packets, typically about the size of a pea, that Canada jays attach to branches all throughout their territories using their sticky saliva that dries almost like glue. These packets are likely more exposed to sun and warm temperatures than food stashed in a log or hollow tree, which means they’re more subject to deterioration if temperatures are too warm. That’s not traditionally been an issue for Canada jays, but times are changing.
Canada jay numbers have proven to be on the decline elsewhere in the southern parts of their range. “Our numbers suggest northern Minnesota may be seeing the same unfortunate phenomenon,” said Wilson.
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I noticed that about 8 years ago, blue jays which I use to see in low numbers were everywhere and Canada jays were hard to find.
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