hedgeblog

HIBERNATION, WHAT IS IT?

When Autumn arrives, the natural food for hedgehogs becomes scarcer, till it gets to the point when the hedgehog is using more calories looking for food than it can get from eating what it finds. When birds face this problem, they simply fly away to warmer places where food is abundant. The hedgehog can`t do this and adopts the alternative strategy of becoming inactive and using as little energy as possible until the weather and food supplies improve.

One of the most energy-expensive activities is keeping the body warm, especially for poorly insulated hedgehogs. So, to save energy, they abandon the attempt; the body furnaces are allowed to burn out and the hedgehogs temperature falls from about 35c to 10c or less, to match its surroundings.

In very cold conditions, the metabolic engines are stoked up gently so as to ensure that the body does not fall below 1c and risk frostbite or freezing solid.

Allowing the body to cool, saves a lot of energy, but in consequence all the chemical activities like nerve conduction, digestion, growth breathing and movement are slowed right down to almost a standstill.

The heart rate slows to less than 20 beats per minute; respiration almost stops altogether and an hour may elapse between short bursts of breathing. These changes economize further on energy expenditure, but the price of complete immobility and major changes in the chemistry of the body that cannot be swiftly reversed. Nevertheless, energy consumption in hibernation is reduced by over 90%, the hedgehogs way of overcoming the problem of food shortage in winter.