ReindeerAs Christmas approaches, I’m reminded of the days when my sons were small and we (righ

ReindeerAs Christmas approaches, I’m reminded of the days when my sons were small and we (rightly or wrongly) encouraged their belief in that “jolly old elf” and flying reindeer. The requisite cookies and milk were left out, along with carrots and celery sticks for the reindeer (as I recall, somebody else consumed the cookies and I got stuck with the vegetation…). When little boys needed to go to bed so that Christmas magic could occur, the sound of sleigh bells could be heard outside the house, causing them to dive under the covers and squeeze their eyes tightly shut.Although reindeer did not become associated with the holiday of Christmas until 1822, when mentioned in Clement Clarke Moore’s poem, “An Account of a Visit from St. Nicholas,” Rangifer tarandus have definite connections to snow and ice. Found in the biome known as the taiga (the Russian word for snow), reindeer have been a central part of the cultures of nomadic herders in parts of Scandinavia and Mongolia for thousands of years, where the animals were depended upon for meat, milk, and transportation. In many places, these cultures are disappearing as younger generations move away from traditional roles and lands.Born in early spring, when much of the taiga is still covered in snow, reindeer calves are protected from the extreme temperature changes at birth (as much as a 50-60°C drop in temperature) by large deposits of brown fat. Unique to mammals, brown fat is an adaptation for generating heat. Filled with mitochondria, the energy-producing organelles of the cell, the brown fat contains a network of capillaries that carry the generated heat throughout the body. Mostly active over the first month of life, the brown fat gradually changes and becomes more like white fat.Well-adapted for living in arctic climates, reindeer also possess a smaller surface area-to-body-mass ratio to reduce heat loss, as well as a winter coat made up of thick, hollow guard hairs over a woolen-like underfur. Because of these and other adaptations, these cousins of the caribou are able to tolerate temperatures below -30°C (-22°F).Reindeer are cousins to the caribou found in other artic areas, such as Alaska, both being subspecies of Rangifer tarandus. Both are also migratory ungulates (hooved mammals), although reindeer tend to be more confined to specific home ranges than are caribou. Reindeer also tend to be stockier than caribou, with a flatter face and shorter legs. Both males and females of the species grow antlers (a trait not found in any other species of deer), which appear while they are still calves. Bulls and non-gestating females will typically drop their antlers in the winter, but pregnant females retain theirs until spring. This adaptation allows her to protect her food sources (mainly reindeer moss, a form of lichen) throughout the winter and thus ensuring sufficient nutrition for the developing fetus. She will drop her antlers within days of giving birth.CWImagehttp://bit.ly/1OBbn7ISourceshttp://reindeer.salrm.uaf.edu/about_reindeer/http://www.reindeerherding.org/herders/sami-norway/http://bit.ly/1QPwK9Mhttp://www.mnh.si.edu/arctic/html/caribou_reindeer.htmlhttp://www.blueplanetbiomes.org/taiga.htmhttp://www.uaf.edu/files/snre/MP_04_07.pdfhttp://reindeer.ws/info.htm -- source link

More pics about