Today's News
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caribouElizabeth Curley (ecurley@mail.gbes.orange.k12.nc.us)Sat, 19 Apr 1997 09:48:09 +0000
> [Caribou] [Caribou] > > * Challenge Questions [Image] > * Caribou Field Data > * Journey North News > * Ask the Expert Caribou Migration Update: February > * Related Resources 6, 1997 > > [Today's News] Robert Mulders > Today's News > Once again this season, [Image] > [Migrations and Signs of Spring]biologist Robert Mulders > Migrations and sends greetings and caribou data > Signs of Spring from his office near Hudson Bay in > the town of Arviat (Eskimo Point), > [Report Your Sightings] Northwest Territories. After reading > Report Your Sightings yesterday's manatee report from > Florida , one can't help but wonder > [Teacher Discussion] how welcome a warm water bath would > Teacher Discussion feel to a caribou. Conditions in the > arctic are extreme, and caribou have > [Search Journey North] amazing adaptations for survival. > Search Journey North Imagine roaming around on all fours > in temperatures at -45 degrees F, > return to: and spending several months in > [JNorth Home Page] almost constant darkness. This very > moment, while Ester, June, Cleburne > & company are basking in Ranger > [A/CPB Home] A/CPB Wayne's hotsprings, what do you > suppose our caribou are doing? > > After reading today's caribou data > (posted below) and locating the > caribou, see if you can answer this > Challenge Question: > > Challenge Question #1 > > "What is the temperature > today for caribou # 6977? > (And for extra credit: > What is the photoperiod?)" > > To respond to this question please > follow the instructions at the end > of this report. > > In future updates, we will provide > sunrise/sunset data so you can watch > how dramatically photoperiod changes > in the arctic, and see how this > affects the lives of the caribou. > (Remember: "Photoperiod" refers to > the length of time there is > sunlight. You can figure the > photoperiod by counting the amount > of time between sunrise and sunset.) > > Click Here for Caribou Data > > For 8 months of the year, caribou > habitat is covered with snow. Snow > conditions influence where caribou > are able to travel, and the > availability of their food. With > their keen sense of smell, they can > find food even when its buried under > layers of snow. The caribou's > challenge is not only to survive the > winter, but to have the energy and > strength they will need for the > spring migration. Ironically, when > the snow finally begins to melt, > conditions can be worst of all. Snow > that melts on warm spring days can > re-freeze when temperatures drop, > making it impossible to dig for > food. > > The caribou's winter diet is > predominantly lichens. Lichens grow > very, very slowly. Because the > growing season is so short, it can > take several decades for a lichen to > grow a few inches. Then, in one > bite, it's gone! This helps explain > why caribou need so much room to > roam. After all, the food they eat > today will not grow back for many > years. In the arctic, life is strong > and fragile at the same time. > > Robert Mulders describes the > caribou's winter food: > "There are several hundred species > of lichens in this region. Caribou > are one of the few animals that can > eat this abundant plant because of > the acid it contains. Lichens are > high in carbohydrates and have the > most food value of any plant > available to the caribou. Lichens > are very, very slow growing. As a > rule of thumb, it can take 50-100 > years for lichens to grow back. The > growing season in the arctic is > short--in some places as few as 40 > days a year--and lichens grow only > around 1/16 of an inch per year. So > if an area is overgrazed or burned > the caribou won't be able to use > that habitat for many years. In > fact, there have been fires in > northern Manitoba within this herd's > winter range and we're concerned how > this might affect their use of the > area. > > "In the wintertime, caribou obtain > the lichens by 'cratering' through > the snow. When we go out for field > studies in late March we've seen > instances where they've cratered > through snow as much as 2 feet deep. > In most winters they can forage > without difficulty but some years > starving can occur if an icy cover > forms and prevents them from > obtaining food easily." > > Many lichens are very sensitive to > pollution in the air. When there are > too many harmful things in the air, > lichens die. This is why they are > sometimes called "indicator" > species. They can tell us if the air > is clear and clean. Even in the > remote arctic, pollution has > contaminated lichens. Pollutants > have drifted through the atmosphere, > appeared in the lichens, then in the > flesh of the caribou--and then in > the humans who eat the caribou. > Through studies of arctic women who > are nursing their babies, these > contaminants are known to even reach > babies when they drink their > mother's milk. > > How to Respond to Challenge Question > #1: > > 1. Address an E-mail message to: > jn-challenge-caribou@learner.org > > 2. In the Subject Line of your > message write: Challenge Question #1 > > 3.In the body of the message, answer > this question: > > "What is the temperature > today for caribou # 6977? > (And for extra credit: > What is the photoperiod?)" > > Try this! > Write a vacation postcard from a > manatee to a caribou. Using today's > weather information, compare and > contrast the places these two > creatures inhabit. Be as descriptive > as you can. What does each animal > experience in the course of a day? > In what ways are your habitats > different? Are there any ways in > which they're the same? > > The Next Caribou Migration Update > Will be Posted on February 20, 1997.
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