Hit Snooze: An Imperiled Hibernator Assesses Spring Snow Conditions to Decide Whether to Terminate Hibernation or...

Area of Science:

• Zoology
• Ecology
• Animal Behavior

Background:

• Seasonal changes in physiology and behavior are common in animals.
• Hibernating mammals exhibit extreme seasonal alterations, with timing impacting fitness.
• Environmental cues for hibernation timing are crucial for climate change adaptation.

Purpose of the Study:

• Investigate the cues influencing hibernation termination in Northern Idaho ground squirrels (Urocitellus brunneus).
• Test the hypothesis that squirrels assess surface conditions before ending hibernation.
• Understand variation in hibernation phenology in this threatened species.

Main Methods:

• Attached geolocators to free-ranging Northern Idaho ground squirrels.
• Monitored emergence timing and re-entry into torpor.
• Correlated re-entry behavior with environmental factors like snowpack and season.

Main Results:

• Northern Idaho ground squirrels frequently reentered torpor after initial emergence.
• Re-entry into torpor was more likely earlier in spring and with greater snowpack.
• Females reentered torpor with shallower snowpack than males.

Conclusions:

• Northern Idaho ground squirrels facultatively adjust hibernation termination based on surface conditions.
• This behavior, particularly re-entering torpor, offers a potential mechanism for climate change resilience.
• Further research on facultative emergence timing in hibernators is needed to predict climate change persistence.