As Mel Torme wrote in "The Christmas Song," "They know that Santa's on his way, He's loaded lots of toys and goodies on his sleigh, And ev'ry mother's child is gonna spy, To see if reindeer really know how to fly."
As one zoologist tells it, they do -- sort of.
"Squirrels have a flap of skin that allow them to glide and bats, the only mammal that has true wings, can truly fly, but a reindeer leaps -- they are serial leapers," Tony Vecchio, zoologist and director of the Oregon Zoo, told United Press International's Animal Tales.
"A 600-pound reindeer can clear a river with a jump and a glide because it has a very elastic tendon like a gazelle that allows it to bounce and maintain a leap by keeping its legs stiff and strong."
Vecchio, the animal biologist who helped on the book, "The Flight of Reindeer: The True Story of Santa Claus and His Christmas Mission," by Robert Sullivan, said studying flying reindeer is an evolving field and he is surprised more people do not enter it.
Reindeer is the European term for members of the deer family known to pull Santa's sleigh, but in the United States they are known as caribou.
Caribou once roamed most of North America, they have been traced as far south as Nevada and Alabama, but because of habitat disruption and over-hunting in the lower 48 states, only a small herd of woodland caribou remain -- in Washington state -- although there are an estimated 2 million to 3 million in Canada.
"Walker's Mammals of the World" estimates there are 3 million domesticated reindeer in the world, mostly in Russia.
"Most agree that the reindeer was domesticated in Eurasia 3,000 years ago, although some argued that reindeer were domesticated before dogs," Vecchio said. "Herds of domesticated reindeer are still kept in Scandinavia and Russia but the wild reindeer taste more gamey, similar to the difference between a wild turkey and a domesticated turkey."
Native populations in Europe and Asia herd domesticated reindeer and much like the American Indians who hunted and used every part of the buffalo, every part of the reindeer is utilized from the meat to the hides to the sinews for thread.
The Tsaatan tribes of Mongolia are called reindeer people because their entire nomadic lifestyles are centered on caring for their herds. Tsaatan children are taught to ride reindeer at a very young age and older children are expected to teach their younger brothers and sisters how to handle the herds.
"In Lapland the people make fermented reindeer milk which they say is rich and smooth like Bailey's Cream," Angela Baier, spokeswoman for the Denver Zoo that has reindeer in its collection of North American animals, told UPI's Animal Tales. "Only females retain their antlers in the winter so we know that Santa's reindeer are all female -- so Dasher, Dancer, Prancer, Vixen, Comet, Cupid, Donner and Blitzen are females."
The town of North Pole, N.Y., which features Santa and his nine reindeer, opened in 1949 and soon became the first outdoor theme park. In those days, Santa and his reindeer attended many parades including the Macy's Thanksgiving Day parade in New York City.
"We have nine reindeer and a license to breed and display them and we allow people to actually touch them year-round," Monica Carrow, of Santa's Village, told UPI's Animal Tales.
Still open today, Santa's Village gives children one of the few places to pet reindeer, although reindeer are kept in a few zoos, including the Denver Zoo, the Cleveland Metroparks Zoo and the Point Defiance Zoo in Tacoma, Wash.
Sylvia Cukan, who petted reindeer at Santa's Village, said they are woolly to touch and very soft.
The flying reindeer is a unique subspecies. Its scientific name is Rangifer tarandas pearyi. Known as the Peary reindeer, it is white and lives in the most northern sections of North America
"All reindeer have broad hooves which enable them to walk on and dig in deep snow or soft ground and the Peary reindeer use their hooves to find and scrape lichens which make sup the most of its diet in the winter," Vecchio said. "The Peary reindeer are the smallest in the deer family, smaller than the white-tailed deer -- that's where the 'eight tiny reindeer,' comes from."
A bull moose can weigh 1,700 pounds, a female moose about 1,000 pounds, a reindeer about 200 pounds but the Peary reindeer -- named after Admiral Robert Peary, the U.S. explorer, who is credited with being the first person to reach the North Pole -- weighs less than 150 pounds.
"Walker's Mammals of the World" says the Peary reindeer live in the Alaska Archipeligo and northern Canada and are known as "island hoppers" because of their great leaping ability. They number fewer than 3,600 and are officially designated as endangered.
Loss of habitat, blockage of migratory routes by fuel pipelines, poaching and icebreaker activity make it more difficult for animals already living on the edge in a harsh climate, Vecchio said.
"Disturb a forest in New York and in 50 years the forest will be back but disturb the tundra and it can take hundreds of years to come back and in the meantime the animals -- particularly the larger mammals that have adapted to the tundra environment cannot adapt to a changed environment for several generations," Vecchio said. "That's why drilling in the Arctic National Wildlife Refuge is such a concern."
Biologically, we have several theories on how the Pearys manage to leap such great distances, we think they must have a similar circulatory system to that of whales -- when whales dive their blood stops circulating to everywhere except the brain, Vecchio said.
"Another theory is that as a bird can fall asleep with its claws wrapped around a branch and not fall off because (when) the bird's muscle (is) relaxed (it) is clenched and it takes energy to unclench and in the Peary it takes less energy to leap."
According to Vecchio, the Pearys' natural snap of the leg tendon allows it to leap 6 feet in the air, glide and while in the air to conserve energy.
"Whenever we see pictures of Santa, the reindeer are always at an angle as they leap up or as they're coming down, it's all snap and glide," Vecchio said. "We're also looking at hollow bones that make birds lighter for flight and the Bernoulli Principle -- air travels slower on the bottom (creating more pressure) and faster on top (creating less pressure keeping a plane in the air -- from the Pearys' antlers."
Another theory is that the Peary fur is similar to a polar bear's fur -- the hair shaft is pigment-free and transparent with a hollow core that allows for more buoyancy.
What most people do not realize is that one can get most places in the world by island hopping, the Great Circle route from North America to Europe is a good example, according to Vecchio.
"What is really lacking is first-hand observation, although many have heard reindeer on the roof on Christmas Eve it's hard for a biologist to observe when we only have one day a year to do it," Vecchio said. "And it's usually bad weather Christmas Eve."