May 4, 2024

New Study Reveals How Climate Change Can Change Hibernation Patterns

Helen Chmura, lead author for this latest research study, started the analysis while a postdoctoral fellow at the University of Alaska Fairbanks in 2018 and now works as a USDA Forest Service researcher with the Rocky Mountain Research Station. “Our information show that the active layer, the soil layer above the permafrost, freezes later on in the fall, does not get as cold in the middle of winter, and thaws a little earlier in the spring.” She included, “These modifications, totaling up to about a 10-day decrease of the time soil is frozen at a meter deep, have happened over simply 25 years, which is relatively rapid.”
A juvenile arctic ground squirrel foraging near Toolik Field Station in northern Alaska. Credit: Cory Williams/Colorado State University
Arctic ground squirrels make it through severe Alaska winters by hibernating for over half the year, considerably slowing their lungs, brain, body, and heart functions. They still must invest energy to produce adequate heat from saved fat to keep tissues from freezing. They resurface from their burrows more than 3 feet below the ground each spring, excited and hungry to mate.
Chmura and Williams, along with co-authors, examined long-lasting air and soil temperature data at two websites in Arctic Alaska in conjunction with data gathered utilizing biologgers. They determined stomach and/or skin temperature of 199 free-living specific ground squirrels over the exact same 25-year period. They found that women are altering when they end hibernation, emerging earlier every year, however males are not. Changes in women match earlier spring thaw. The benefit of this phenomenon is that they do not need to use as much kept fat during hibernation and can begin foraging for roots and berries, seeds, and shoots quicker in the spring. Researchers believe this could result in much healthier litters and greater survival rates.
The disadvantage is that if the males also do not shift hibernation patterns, there eventually might be an inequality in offered “date nights” for the males and females. Ground squirrels are likewise an essential source of food for lots of predators, such as wolves, eagles, and foxes. An indirect effect of being active above ground longer is higher exposure and threat of being eaten.
What will occur to the population is a big unidentified — there are unclear winners or losers. While hibernation requires less energy, which might help overwinter survival, ground squirrel numbers likewise depend upon how predators react to climate shifts. For now, Williams concludes, “Our paper reveals the importance of long-term datasets in understanding how ecosystems are reacting to climate change.” Chmura concurred, adding, “It takes a great team to continue a dataset like this for 25 years, especially in the Arctic.”
Recommendation: “Climate change is changing the physiology and phenology of an arctic hibernator” by Helen E. Chmura, Cassandra Duncan, Grace Burrell, Brian M. Barnes, C. Loren Buck and Cory T. Williams, 25 May 2023, Science.DOI: 10.1126/ science.adf5341.
Other contributing authors consist of Brian Barnes, University of Alaska Fairbanks, and Loren Buck from Northern Arizona University, who both started this study in the 1990s to learn how Arctic ground squirrels survive such long, cold, dark, winters and just how cold their hibernation areas were. These concerns prompted them to install the first soil temperature displays, and as technology enhanced, they were able to determine those temperatures all winter long. Cassandra Duncan and Grace Burrell helped with the research study while trainees at the University of Alaska Fairbanks.

Near Toolik Field Station in northern Alaska, an arctic ground squirrel pokes its go out of a burrow. Credit: Oivind Toien/University of Alaska Fairbanks
Unique long-lasting research study sheds light on how biological actions to climate shifts.
Arctic ground squirrels possess an unique quality among mammals– they can withstand freezing even when their body temperature levels fall below the freezing point, permitting them to make it through severe winter season environments. A recent study published in Science that reviews over 20 years of environment and biological information exposes some interesting discoveries. These consist of shorter hibernation times and unique distinctions in between the hibernation patterns of females and males. Surprisingly, female squirrels appear to get up slightly previously in response to warming, a phenomenon that could create a variety of impacts, both favorable and unfavorable, across the food cycle in these environments.
The study was led by Cory Williams, an assistant teacher in the Department of Biology at Colorado State University. Williams embarked on his exploration of arctic ground squirrels while studying at the University of Alaska Fairbanks more than a half and a decade ago.
” I believe the important things that makes our research study distinct is that we are looking at a long enough dataset to show the impacts of climate modification on a mammal in the Arctic,” stated Williams, who signed up with the CSU faculty in 2021. “We can reveal a direct link in between changes in temperature and the physiology and ecology of these animals.”

Arctic ground squirrels have an unique trait among mammals– they can withstand freezing even when their body temperatures fall below the freezing point, permitting them to make it through harsh winter environments. Arctic ground squirrels survive severe Alaska winter seasons by hibernating for over half the year, drastically slowing their lungs, body, brain, and heart functions. Chmura and Williams, along with co-authors, examined long-term air and soil temperature data at 2 sites in Arctic Alaska in combination with information collected utilizing biologgers. While hibernation requires less energy, which might assist overwinter survival, ground squirrel numbers also depend on how predators respond to environment shifts. Other contributing authors consist of Brian Barnes, University of Alaska Fairbanks, and Loren Buck from Northern Arizona University, who both began this study in the 1990s to discover how Arctic ground squirrels endure such long, cold, dark, winters and simply how cold their hibernation spots were.