Canada Jays (Perisoreus canadensis; formerly Gray Jays) are denizens of the north country. As a habitat specialist, Canada Jays are only found among the firs, spruces, larch, and aspens of the boreal forest. Their habitat is characterized by a short growing season, where most plants have less than 100 days without snow. For 8 to 10 months of the year, boreal forests can be a harsh, unforgiving, and seemingly food-less landscape. Bitter cold, biting wind, and lots of ice and snow characterize this region. When the majority of the landscape is covered in white and most things appear to be dead, it is hard to imagine how anything could survive in such a place.
Despite the apparent odds, many animals (and plants!) have developed unique adaptations to survive the winter months, including Canada Jays. As a long-term caching species, Canada Jays store food beneath the bark of trees to last them throughout the year. Canada Jays are unique among food-caching species, however, as they store perishable food rather than more durable foods like nuts and seeds. As opportunistic eaters, Canada Jays eat and cache whatever they can find, like berries, small animals, carrion, arthropods, fungi, and even human food.
Despite the apparent odds, many animals (and plants!) have developed unique adaptations to survive the winter months, including Canada Jays. As a long-term caching species, Canada Jays store food beneath the bark of trees to last them throughout the year. Canada Jays are unique among food-caching species, however, as they store perishable food rather than more durable foods like nuts and seeds. As opportunistic eaters, Canada Jays eat and cache whatever they can find, like berries, small animals, carrion, arthropods, fungi, and even human food.
Canada Jays' reliance on perishable foods puts them at unique risks compared to other species that cache food for long periods of time. When foods are perishable, they are at risk of spoiling in certain conditions. The easy fix to this potential problem, however, is to store foods at subfreezing temperatures. This solution is conveniently attainable in such a place like the northwoods, where the environment itself acts like an outside freezer. With temperatures that regularly stay between -20 and -40°F, the foods that Canada Jays cache can stay fresh for months at a time.
Climate change, nonetheless, changes all of this. Warming temperatures, longer periods of drought, and disruption of freeze/thaw cycles are just some of the many effects occurring with global climate change. Moreover, these effects are amplified at higher latitudes, where boreal forest dominates. Warming temperatures increase the frequency of freeze/thaw cycles, preventing the "deep freeze" of winter from happening in such ecosystems. This deep freeze is absolutely critical for species like Canada Jays, since their cached food would otherwise go bad quickly in warmer environments.
At Algonquin Provincial Park in Ontario, a population of Canada Jays has been extensively studied for over 40 years. In this time, the population has declined by over 50 percent. Important research by retired Algonquin Chief Naturalist Dan Strickland and Dr. Ryan Norris and his lab at the University of Guelph has examined many hypotheses explaining their decline. Several studies have shown that the relationship between climate and food is important for the persistence of Canada Jays.
At Algonquin Provincial Park in Ontario, a population of Canada Jays has been extensively studied for over 40 years. In this time, the population has declined by over 50 percent. Important research by retired Algonquin Chief Naturalist Dan Strickland and Dr. Ryan Norris and his lab at the University of Guelph has examined many hypotheses explaining their decline. Several studies have shown that the relationship between climate and food is important for the persistence of Canada Jays.
While climate change spells bad news for Canada Jays in Ontario, we do not yet know how it may affect other populations, especially at higher latitudes. Presumably, Canada Jay populations at higher latitudes may be at even greater risk, since the effects of climate change are more pronounced at northern climes. To understand how Canada Jays may be faring in a changing climate, we initiated a study at Denali National Park and Preserve in 2016. In collaboration with Dr. Ryan Norris and Dr. John Marzluff at the University of Washington, we are investigating several hypotheses testing cache quality, caching behavior, and food limitation in Canada Jays. For more information about this study, see more about the Denali Canada Jay Project and this article.
Header Photo © Sean Tevebaugh