Winter - The Wow Season

Hibernation Station!

We know that bears thumb their nose at winter by hibernating.

How does hibernation work?

One important, useful, and effective strategy to survive winter is the conservation of energy. While humans might conserve energy by curling up beneath an electric blanket, animals have other methods they can use. One method is that they can survive just fine by letting their body temperature drop. This lower body temperature saves energy.

When the body temperature drops, the animal is said to be in a dormant state. Those that are only in this dormant state for a short period of time are in torpor. Those that dominate for a long time (as much as nine months!) are in hibernation. Dormancy conserves energy through lower body temperature, breathing rate, and lowered metabolism.

Some animals can lower their body temperature almost to freezing.

Some animals may remain in a state of torpor all day, except for a short time to awaken to eat. How much energy can an animal save using these dormancy methods?

•13 line ground squirrel, 1/50th of its normal energy •Richardson ground squirrel, 1/90th of its normal energy Animals are able to time their dormancy periods depending on their age, sex, weight, and many other factors, as well as location in the nivean environment, such as on a southern slope or in an alpine meadow. All animals are ultra-sensitive to even small changes nature makes as the seasons progress.

Even during hibernation, animals may awaken partially or fully. This is called arousal. Some feed; others don’t. The dens where animals hibernate are called their hibernacula.

16 ©Carole Marsh • Gallopade International • 800-536-2GET • www.gallopade.com • Winter - The “WOW!” Season

Hi(bear)nating and Other Facts!

Animals that hibernate recycle their urine through their kidneys, bloodstream, and into their saliva, where it is swallowed, and the cycle starts again. This keeps the animals from getting dehydrated while in hibernation and also keeps them from having to wake up to eliminate these wastes.

Animals that hibernate have a hormone (HIT) that triggers the fall in body temperature, a slower pulse rate, and a decreased appetite.

Scientists have learned a lot about hibernating bears by sneaking into their dens in winter and taking their temperature by putting a thermometer into the bear’s rectum. (Sometimes, the scientists learned that the bears were not as sound asleep as they thought and were not particularly happy at this unexpected intrusion!)

Animals like moose and elk use their fur as an insulator during the winter. The fur absorbs radiation from the sun and filters it on to the animal’s skin, if the extra heat is needed, or radiates it back off if it is not.

Some animals eat so little during the winter that they become malnourished.

Some animals aggregate, or gather the entire group into a ball, to reduce the surface exposed to the cold, which helps them stay warm.

Some creatures, such as adult eagles, often conserve much-needed winter energy by stealing food that younger eagles have caught instead of hunting for themselves.

Some smaller animals, such as a weasel, will kill other animals (a lemming, for example) in order to get its fur to line its nest with.

Animals that die or are killed in the winter are referred to as winter kill.

17 ©Carole Marsh • Gallopade International • 800-536-2GET • www.gallopade.com • Winter - The “WOW!” Season

Migration Station One way that many animals cope with winter is just to get out of its way! Some animals migrate “horizontally” to the southern hemisphere or to the tropics. Other animals migrate “vertically” to lower, and therefore, warmer altitudes.

The amazing arctic tern migrates from above the Arctic Circle to the southern hemisphere just above the Antarctic Circle each year, a distance of more than 10,000 miles (16,093 km)! Canada geese migrate only from the Arctic Circle to Wyoming.

Some animals can migrate just a few miles down a steep mountainside and achieve the same goal as travelling many more miles in a horizontal distance. For example, moose may merely move from upper forest meadows down to willow-lined stream bottoms.

Animals that do not migrate soon enough in autumn may find themselves trapped in winter conditions that they may not be able to survive.

At the National Elk Refuge near Jackson Hole, Wyoming, you can see almost 12,000 wintering elk each winter!

Animals do not migrate at the same time. Some begin their journey sooner, others later. Some travel quickly because they sense winter coming on. Others take their time if conditions remain mild during migration.

Some people even migrate during the winter! Those that head from the northeastern and other parts of the United States to Florida and other southern states are called “snowbirds.” Of course, some of us migrate to winter, especially to ski slopes and snowmobile parks, where we think winter survival is fun!

18 ©Carole Marsh • Gallopade International • 800-536-2GET • www.gallopade.com • Winter - The “WOW!” Season

Other Ways Animals Prepare for Winter Change of diet: Animals may not be able to feed on their usual plants, which may die out in winter or be buried beneath the snow.

Therefore, they switch to other food sources.

Cast: Some animals such as an elk shed (cast) their antlers which helps them conserve energy.

Molt: Many animals undergo a color change to prepare for winter. The snowshoe hare is an example. Most often, animals achieve this color change by molting, in which each dark hair comes out and is replaced by a white hair. This new white coating, called pelage, is not only beautiful, but protects the animal by providing it camouflage against the snow so that its predators are less apt to see it when hunting.

Legend Lore

Many old-timers, farmers, and others associate changes in animal behavior in the winter with different meanings. Some say that when animals grow a thicker coat of fur, it is a prediction of an especially severe winter to come. However, scientists believe these thicker coats are actually a result of summer weather, not winter. In the same way, don’t assume that spying animals busily gathering seeds means an especially cold winter; it may just mean that there was a good summer crop of seeds!

Indian Summer or “false spring” is a return of warmer weather after fall has begun to turn to winter.

Amazing Fact!

During the Armistice Day storm of 1940, 59 sailors died on Lake Superior and Lake Michigan when winds reached 67 miles per hour!

19 ©Carole Marsh • Gallopade International • 800-536-2GET • www.gallopade.com • Winter - The “WOW!” Season