Caribou Migration Update: May 22, 2002 Today's Report Includes: Latest from the Arctic Front Big News! Ice-Out on the Porcupine River I See Sea Ice: Discussing Ice and Challenge Question #21 Salty Sea and Frazil Ice Arctic Culture and Caribou: Showing What You Learned this Season Antlers! Discussion of Challenge Question #20 Dempster Highway: Discussion of Challenge Question #20 Year-End Evaluation: Please Share Your Thoughts! Latest from the Arctic Front Caribou Migration Map Click on Map to Enlarge With springtime conditions we know the caribou are moving toward the calving grounds. Porcupine River ice has broken up in Old Crow and they report caribou moving through. Unfortunately at this time, the data shows little evidence that the animals are moving. Because the management team is concerned that some people may use the locations of the herd to their benefit and without regard to the animals, the data we are given has been held for 2 weeks before they send it. Stay tuned if you can! Today's Data We will continue to post data and maps of the caribou locations through the month of June until the caribou have reached their calving grounds. Big News! Ice-Out on the Porcupine River One of the big signs of spring is the break up of ice and the return of the moving waters in rivers of the Arctic. This week we learned news from Old Crow that the ice on the Porcupine River went out on May 17, at 2:00AM. Lone caribou floating down the Porcupine River on an ice floe. Time to swim! Find out more news and information at the Old Crow Web site. I See Sea Ice: Discussing Ice and Challenge Question #21 Courtesy of the National Snow and Ice Data Center During late May or early June, the ice in the Beaufort Sea begins to melt, first forming a band of open water along the coast. This band of water may open or close as wind pushes the ice floes either toward or away from shore. "If the ice covers 16 million square kilometers in late winter and 9 million square km in summer, what percent of the ice melts away with the change of the season? Do some math to calculate your answer." Here are some simple calculations needed to solve this question: 9 million kilometers square (km2) subtracted from 16 million km2 will give you the amount of sea ice that has melted. 7 million km2 has melted. To calculate what percentage of ice melts away with the change of season, think: the total amount of sea ice in winter is about 16 million km2, and 7 million km2 melts, divide 7 by 16. If you followed these steps, you should have calculated that about 44% of the ice melts away in the summer. Salty Sea and Frazil Ice Arctic view The ocean is a salty place. If you have ever tasted a mouthful of sea water while you were swimming you know that it is salty. Does salty water freeze like fresh water? How do freezing temperatures affect water? Molecules of water move closer together until the water reaches 4 degrees Celsius. Then the molecules of water begin to push apart. The coldest water (at 0 degrees C., the freezing point of fresh water) forms an ice layer that is lighter than water, so it floats. To picture this, think of people standing in a circle, shoulder to shoulder, and holding hands. As the temperature drops, 4-3-2-1-0 each person begins to move apart until everyone's arms are straight out to their sides. This creates a lot of space between each person, and this space fills with AIR. The air makes the ice lighter than water, so the ice floats on the surface. How is salty sea ice different? What is "frazil" ice? Read an expert's description: The Nature of Sea Ice Arctic Culture and Caribou: Showing What You Learned this Season Chandalar in winter Courtesy S. Kalinowski Although this is not the final caribou report for the season, the next few reports will be migration updates with maps and data primarily. In this report we would like you to take a quiz to show what you have learned this year. Don't worry, it should be fun and make you think and maybe do some further research for some through answers! First, the questions, then when you have them answered (wait until you are all finished!) you can link to the answer page. What Did YOU Learn About Caribou? True or False 1. Only caribou bulls (males) have antlers. 2. The Sierra Nevada Mountains are one of the mountain ranges found within the Porcupine Caribou migration range. 3. The caribou's favorite winter foods are nuts and berries. 4. Native Gwitch'in people have always used plastic beads, scrapers and spoons. 5. In April, the U. S. Senate voted against drilling for oil in the Arctic National Wildlife Refuge (ANWR). 6. Many native (aboriginal) people live off the land in the Arctic. Explain your Answer 1. Why are the individual hairs in the caribou's fur hollow? (This is an adaptation.) 2. There are no paved roads inside ANWR. Why? 3. Old Crow, Yukon Territory, a small town of 300 aboriginal people is located at the confluence of the Crow and the Porcupine Rivers. If you wanted to visit, how would you get there? (Think summer and winter.) 4. Trudy was not an old caribou when she died this spring. What are the best guesses about how she died? 5. Can you walk across the Beaufort Sea in the winter? Why? 6. List some of the reasons caribou cows have adapted to having their calves on the coastal plain? 7. Daylength has changed significantly in the Arctic since February. Use this table to help: Date Sunrise Sunset Hours of Daylight  02/04/02  10:18 16:50  you calculate 05/20/02 2:47 23:51 you calculate Calculate how much daylight there was on Feb. 4. How many more hours of light do they have May 20? How many hours have they gained? Answers can be found here (don't peek until you're done!): Caribou Quiz Answer Page Antlers! Discussion of Challenge Question #20 Arctic National Wildlife Refuge, June 2001 Amy Gulick In our last update, caribou biologist Doug Urquart described the seasonal differences between the antlers of males and females. We wanted you to think why the pregnant females keep their antlers until after giving birth in the spring while males drop theirs after the rutting season in the fall. By looking at when antlers are shed we can see some of the interesting ways that the pregnant females have adapted. Shedding antlers after calving allows: Pregnant females use their antlers to defend their feeding craters (craters in the snow) from antler-less males. Energy needed to build developing antlers is expended after calves are born, reserving energy earlier for calf fetus development. Dempster Highway: Discussion of Challenge Question #20 The Dempster Highway, a 457 mile road into the Arctic has paved the way for easy access to a land that before 1979 was difficult to access. How do you answer this, "What effects might the Dempster Highway have on caribou behavior and travel?" Because this narrow strip of gravel is the only road within the vast range of the Porcupine Caribou Herd, and every year a large proportion of the caribou harvested from the herd are taken here. Something new like this has changed life in many ways. There are not a large number of animals harvested (hunted), since numbers show that only 3 to 5 percent of the herd is harvested annually. Hunter safety is important because there are a large number of hunters using the highway. And as in Joe Tetlichi's hunting story, there is a big concern that the traditional hunting ways will be kept and honored by the people. Traffic on the highway could also be a concern. Between May and September, the high traffic season, it is common to have over 100 vehicles travel the roadway daily. Even in the winter months the highway can see up to 40 vehicles daily. Jill, Christine and Amy from Iselin Middle School have a very real concern too: "The caribou don't know what cars are so they won't know to get out of the way. People should also know to be more careful." Year-End Evaluation: Please Share Your Thoughts! Please take a few minutes to share your suggestions and comments in our Year-End Evaluation Form below. The information you provide at the end of each year is the single most important tool used to guide our planning. Journey North Year End Evaluation Please share your thoughts This is the last FULL Caribou Migration Update. Weekly data only updates into June will be published until the caribou have reached their calving grounds. Thank you for making the first season of the Porcupine Caribou Migration a success! The Next Caribou Migration Update Will Be Posted on May 29, 2002. Copyright 2002 Journey North. All Rights Reserved. Please send all questions, comments, and suggestions to our feedback form