I WONDER…. Do animals sense the passage of time?
It’s spring time, when many temperate zone animals are emerging from their winter slumber. Here in the mountains of Washington, high altitude hibernators such as marmots may spend seven months or longer curled up in their dens below the snow, breathing and heart-beating just enough to stay alive. I’ve always wondered - when they wake up, do they have a sense of those long passing months or does it seem like just another night has gone by?
I did a little digging and found there just isn’t much information or even speculation about this question.
A hoary marmot in early spring on Mount Rainier
How do we perceive time?
According to the folks who study time perception, there is a difference between physical and psychological time - which is what I think I’m wondering about. Physical time is objectively measurable as minutes on the clock. But psychological time is trickier. Humans perceive the passage of time through events we experience and this process may be highly subjective. Time can fly when you’re having fun, as the saying goes, or can be excruciatingly drawn out when stuck in a boring meeting - even if each event measures an hour. Over longer time periods, our memories of events give us a sense of time passing based on how long ago events took place and how well we can recall them.
What about animals?
We know that many animals have excellent memory perception. Elephants, primates, and wolves have years or even decades-long associations with places and other individuals bound by experiences instead of instinct. It seems reasonable to infer that they would align these memories with a timeline like we do, understanding events as being both recent and past.
But what about our hibernating friends such as marmots and bears? Do they just wake up and stretch and go about Spring’s business without reflecting on the many months they’ve missed?
When hibernating, a marmot’s heart rate drops from 100 to four beats per minute, its respiration rate slows to one breath every few minutes and its body temperature falls 50 degrees. It sleeps very deeply, waking briefly only every couple of weeks to defecate - and I’d guess that’s probably akin to a trance-like sleepwalk. I know when I wake from a really great sleep it doesn’t feel like eight hours just passed. So I’m guessing that these weeks of sound sleep between bouts of wakening don’t register as any longer than a normal summer sleep cycle would.
But after having “just” gone to sleep with all the pounds they packed on last fall, they’re no doubt wondering why they’re suddenly so hungry!
Grand Teton National Park’s famous Grizzly 399 and her four cubs who spent the last two winters sharing a den during their winter’s hibernation.
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