Thanks to biologist Robert Mulders of Canada's Northwest Territories, the story of his 5 satellite-tracked caribou continues. As you plot today's data, see whether you think the caribou migration has begun.
It's been two weeks since our last report. In that time, the average caribou would have eaten over 150 pounds of its favorite food. What do caribou eat in the wintertime, with all that ice and snow covering the ground?
From Scott Young Public School, Ontario (syoung@web.apc.org) "The barren ground caribou eat ground lichens which they dig up with their hooves."
From Kara, Sarah, Casey and Heather of Estabrook School (esta@cybercom.net) "In the winter, caribou survive generally on ground lichens, sedges, and bark from small trees. During the winter, their home is around Hudson Bay, Canada. Please send more challenge questions about caribou. We enjoy solving them."
From East Hills School, Roslyn, NY (ehills@dorsai.org) "This is Ronny and Alex from Mrs.Berger's 5th grade class. Barren ground caribou eat lichen during the winter months."
We called Robert Mulders yesterday to hear more about the caribou's winter food. Here's what he had to say:
"The caribou's winter diet is predominantly lichens and 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.
"By the way, as you track these 5 caribou, remember each individual is actually part of a large concentration of animals. Caribou are gregarious and are usually found in groups of 50-500 animals. There are 500,000 caribou in this herd and we're watching only 5 of them. Quite a small sample size! A couple of weeks ago my assistant Dave Abernathy flew over a group of about a thousand and caribou #06978 was among them! He actually spotted her from the air.
"I contacted a couple of teachers at the Qitiqliq high school here in Arviat to see whether it might be possible for Arviat students to link up with Journey North. I'll keep you posted."
Challenge Question #14 Now that we know what the caribou eat, find out what eats them! To respond to this Challenge Question please follow the directions at the end of this report.
Here are the satellite coordinates for our 5 caribou through February 16th:
Caribou #06978
Jan 17: 61.370 N, 94.056 W
Jan
22: 61.035 N, 94.013 W
Jan 27: 61.370 N, 94.000 W
Feb 01: 61.374
N, 93.978 W
Feb 06: 61.354 N, 94.093 W
Feb 11: 61.413 N, 94.082
W
Feb 16: 61.425 N, 94.135 W
Caribou #06980
Jan 17:
59.952 N, 96.870 W
Jan 22: 59.952 N, 96.870 W
Jan 27: 59.757 N,
96.907 W
Feb 01: 59.730 N, 96.206 W
Feb 06: 59.689 N, 96.194 W
Feb 11: 59.858 N, 95.949 W
Feb 16: 60.070 N, 95.751 W
Caribou #23924
Jan 17: 61.191 N, 105.213 W
Jan 22: 61.195
N, 106.179 W
Jan 27: 61.291 N, 106.899 W
Feb 01: 61.403 N,
107.446 W
Feb 06: 61.714 N, 107.350 W
Feb 11: 61.554 N, 107.157
W
Feb 16: 61.257 N, 106.866 W
Caribou #23925
Jan
17: 59.731 N, 97.201 W
Jan 22: 59.590 N, 97.580 W
Jan 27: 59.766
N, 97.919 W
Feb 01: 59.830 N, 97.957 W
Feb 06: 59.847 N, 98.049
W
Feb 11: 59.859 N, 97.322 W
Feb 16: 59.978 N, 97.232 W
Caribou #23926
Jan 17: 59.303 N, 98.289 W
Jan 22: 59.398
N, 98.382 W
Jan 27: 59.409 N, 98.495 W
Feb 01: 59.821 N, 99.103
W
Feb 06: 59.867 N, 99.197 W
Feb 11: 59.618 N, 97.524 W
Feb
16: 59.695 N, 97.042 W
How to Respond to Challenge Question #14:
1. Address an e-mail message to: jn-challenge@learner.org
2.
In the Subject Line of your message write: Challenge Question #14.
3.
In the Body of your message, answer this question:
" Now that you know
what caribou eat, can you tell us what eats them?"
The Next Caribou Migration Update Will be Posted on March 7, 1996.
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