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That is the story of how animals hibernate in winter.
Every character within the story might be represented by a unique instrument of the orchestra. As an illustration, the wooden frog might be performed by the flute. And right here’s the painted turtle performed by the bassoon. (Naturally.) The widespread poorwill by the trumpet. The strings will characterize mosquitos. The drums, black bears. And, after all, the Antarctic cod by a theremin accompaniment.
Earlier than we start—
Hibernation is like sleep… however not likely. It’s a interval of psychological and bodily dormancy that varies in species. It simply appears to be like like sleep. As a result of complete new gears are beginning to flip contained in the physique. Metabolism can sluggish to lower than 5 %. Coronary heart beats can drop from 300 per minute to lower than 10. Hibernation is a response of kinds. (Cue archive nature movie: “Heavy snows cowl the Rockies.”) So when winter comes, hibernation begins. (Archive nature movie continued: “Marian once more heads for her den.”) However, not simply throughout winter. It additionally happens in instances of warmth and famine. It’s like life help, however as an alternative of machines and docs, it’s all animal intuition and evolution.
In a snowy wooden, in a gap, there sits a wooden frog. Its coronary heart is stopped and it’s not respiration. As temperatures drop, the frog freezes. Its physique fills with ice crystals. Each winter, like clockwork, the wooden frog produces excessive concentrations of glucose and glycogen in its blood. And one thing akin to a syrupy antifreeze coats its cells. Consequently, its important organs are protected despite the fact that as much as two-thirds of the water within the frog’s physique is ice.
Simply then, a painted turtle breathes by way of its butt in an ice lined pond—form of. A hibernating turtle in water slows its metabolism, decreasing its vitality and oxygen calls for. Unable to floor for air, the turtle does one thing form of wonderful. (Cue turtle solo: “Fiiiiiiiiiiiigaro!”) As a substitute of respiration by way of its lungs, it absorbs oxygen from the water by utilizing elements of its physique which can be thick with blood vessels. That features its pores and skin, mouth, and (ahem) rear finish area.
In an open brush, a typical poorwill is totally nonetheless. If temperatures drop or insect prey is sparse, the poorwill can sluggish its metabolic price and drop its physique temperature. It may possibly survive like this a number of weeks with out meals. Poorwills are distinctive amongst birds for his or her capability to enter this quieted state for an prolonged interval. Not like mammal hibernators of their dens, these birds hibernate out within the open—just about anyplace.
All of the sudden, as chilly takes over in a suburban yard, a male mosquito dies and a feminine bulks up. Feminine mosquitoes can acquire as much as 10 instances their weight in preparation for winter. Then they go right into a diapause, which—not like hibernation—is a whole suspension of growth.
In a gap within the floor (greater than the frog’s, after all), a hibernating black bear breaks down fats tissues. This provides its physique with water and as much as four,000 energy on a regular basis. Muscle and organ tissues break down to produce protein. Crazily, the dorment bear regularly builds new protein utilizing nitrogen from its urine.
Deep at midnight depths of the Antarctic, a cod is semi-comatose. It has lowered its feeding and slowed its coronary heart price—20 instances much less lively in winter in comparison with summer season. Winter water lowers the metabolism of many fish, however within the all the time chilly waters of the Southern Ocean, it isn’t temperature that triggers the cod’s dormancy—it is lack of sunshine. Think about winter within the Antarctic: no solar for months. With out mild, it turns into more durable to hunt for prey—and more durable to outlive. Until, after all, you may hibernate…
The wooden frog. The painted turtle. The widespread poorwill. Mosquitos. The black bear. And, after all, the Antarctic cod.
Girls and gents, “The Sleep Cycle” by L’orchestre D’hibernation Animaux.