European Stars And Stripes (Newspaper) - January 18, 1988, Darmstadt, Hesse Migration incl hibernation ate very cd Liy Ira Lenics observed Peter j so Al the Mountain research station near Boulder Goto ii takes an enormous amount Oler if Ray to Migrate Overland go Only bids and aquatic animal can Doit efficient As far hibernation in s mainly used Al Mitali tucs them arc l Many areas in the a North i hire an animal can Sally sleep through the win let without ire Zingor running out of stored merchant author of a newly published Book on Winter car enology. Life in the cold univ Oreily press of new England pointed Oul Hal most animals and All plants Nusl Slick it out All a sneer and have evolved various mechanisms Lor keeping warm. Some animals that Are normally solitary huddle together with As Many As 20 lying squirrels crammed 1 Inlo a Sec Lon of a hollow tree or three or our species of 5 snakes intertwined in a resell Den. Voles and Deer mice build communal Ness and tunnels under inc insulating Blanket of Snow even in air temperatures As Low As 10 degrees fahrenheit Marchand reported measurements Over a two week period in january showed that Tempo lures hovered around 32 degrees fahrenheit where a deep Snow pack acting As an insulating Blanket met the ground. In Ihoko Ness Tompic Ratuis often reach �0 degrees some warm blooded animals especially Small Birds enter a nightly torpor reducing their body Lom Pearlue i to limit heal 1055 to i to cold night air Bui Many other Winter Active animals have evolved Eta borate Irsch Aniss to generate or save heal. As Wai Chard noted. Some Small Birds that do nol Fly Bough. Such As Gowlin Chet and Redpoll grow More feathers in Winter and Hull Ihm Oul in ing cold Tor added a Stalion. But this is nol enough to lend Oil the fierce Winter cold. To maintain their body temperature and remain warm enough to try some Birds must shiver almost i continuously to generate Clra body heat. Can Lola Carey and Richard l. Marsha showed mat goldfinches acclimatized to Winter can produce 5 5 limes As much heat As usual by shivering. For animals with appendages exposed to the cold such As the legs of ducks or the tails of beavers an interlaced network of blood vessels acts As a heal exchanger to Block excessive loss of heat to the environment. In the exposed extremities surface veins constrict shunting blood toward inc Center there the warmth of arterial blood is transferred la the cooler blood in veins. This keeps Iho extremities Cool but preserves she animal s Core temperature. Plants Loa have evolved Antifreeze techniques. Evergreens Tor example keep the cells in their leaves from freezing and bursting by transferring water in the Colls to the spaces Between cells. Ice crystals lorm outside the cells and press in cell membranes but the fluid within cells is now More concentrated and thus More resistant to freezing. Marchand pointed out that contrary to popular belief the hardest Winter Days for Evergreen plants Are the ones people like Best sunny and Calm. Al these limes the plans Are at risk of death from Dessi Ealion because their dark coloured leaves warm up More of their stored water turns to vapor and they lose moisture to the colder and drier surrounding air. Wind however cools the leaves and diminishes water loss he said. He and his fellow Winter ecologists have also questioned some beliefs about Why animals grow bigger in the North or turn White in Winter. Winter while May be important not so much a a Camou Llaga especially since Winter enemies Aro few As a Means of increasing insulation Marchand said. He explained thai without the pigment Melanin in or and leathers there Aro More air spaces within the hairs and feathers and thus greater insulation. And Marchand suggested larger body size among northerly members of a species such As Fishers and Marlens. May be the accidental result of decreased Competition for food in Tho North rather than a specific adaptation to reduce heat loss or to Siloro extra Energy Tor Winter. For example one study showed Hal the size of the Short Lail weasel increases northward Only alter us Ranger extends beyond that of its closest competitor the Longtail weasel. One of the most successful wining survivors is the smallest of mammals the shrew according to detailed studies by Joseph Morritt. Director of the nature Reserve in Rector a. If there was conf a hyperactive Amman the shrew is it. The Lanc it Torch american shrew Iho Short lolled shrew As much As two 25-cent coins has a heart Rald of to beats a min ulc 70 is Normal for people and respiration rate of 164 breaths a Minuto. Merril i. Who has been studying this Bro St Crl creature by telemetry reports that it lives alone All Winter in an underground nost and races in Routi an elaborate Syllm of tunnels feeding on insect larvae and pupae and occasionally dipping into its to ird of stored live prey. This shrew has a venomous bile that immobilized Pray keeping in fresh Lor Days As an emergency ration. The tiny mammal protects its Cache by defecating and urinating on it which discourages other potential diners. But the shrew s main Winter survival , Merrill s studies have shown is a layer of so called Brown fal accumulated each Winter Over the shoulder fades Brown fat acts like a Furnace or heating a tank when the hypothalamus a tiny gland Al the Hase of the brain is cued by cold it triggers the Lermon a hormone which in turn acts on an enzyme Hal Catalyses the breakdown of fal molecule in fal this breakdown releases heal which warms i
