Spring Migration: Loons are Returning to the BWCAW

Transcription

1 We saw our first loon of the season when moved camp from Knife Lake to Spoon Lake. In honor of that loon sighting, this week's Notes from the Trail is all about migration. Migration means the movement of a group of animals from one place to another. Knife Lake is a very big, deep lake. When we left Knife Lake, the ice was still thick enough to walk on. After our first portage, we were able to switch from walking to paddling because Bonnie Lake was unfrozen. The ice on Knife Lake was still safe for us to walk on.

2 I'll never forget walking down the portage trail and looking out over water (not ice) for the first time this spring. Another sure sign of the season was floating on the surface of the water-- a loon! Loons, along with many other types of birds, are returning to the area after spending the winter in a southern climate. Open Water. Notice the bits of ice. Are there some animals in your area that are only around for part of the year? Usually animal migration is seasonal. Here in the United States, we usually see certain animals heading north in the spring. When fall comes, they head south. That means that spring and fall are busy times for certain animals. Many birds, like the loon migrate. Really, all sorts of different animals migrate. Birds, mammals, reptiles, ampibians, fish and insects migrate. For example, monarch butterflies fly all the way to Mexico for the winter. Some animals travel long distances when they migrate. Others travel a bit, but they don't go very far. Some animals travel from one specific place to another. When all members of a species move, that is called a complete migration. Loons make a complete migation. They spend summers in the northern United States and Canada and winters in the Gulf of Mexico. For some animals, not all members of a species migrate. This is called a partial migration. When a group of animals moves from place to place, that is called nomadic migration. A herd of bison wandering around on the plains is a good example of nomadic migration.

3 Why do you think animals migrate? All animals need food, water and shelter to survive. The most important reason for animal migration is food. They also migrate to avoid extreme cold or heat. When the seasons change, the habitat changes. Loons spend all summer swimming around the lakes in the Boundary Waters Canoe Area wilderness. They fly from lake to lake. They catch fish in the water. They make nests and hatch their eggs on shore. In the winter, the lakes were covered in ice. Loons need access to water to catch fish to eat, and they need water to take off and land. Did you know that a loon's feet are positioned so far back on its body that it can't really walk on land? This adaptation makes the loon a great swimmer though. Sometimes when animals migrate, the way they look changes. When the loons headed south for the winter, they were mostly gray. Now the loons have their summer plumage, which is a black head, black back with white spots, and white belly. This plumage change confused scientists for a while. In the past scientists thought that loons were two different species because they looked and even sounded different between summer and winter. How do you think the animals find their way when they migrate? Somehow salmon know which stream to swim up to spawn. Loon pairs return to the same lake every summer. This is still a mystery in many ways, but scientists have found some clues. Animals that migrate during the day use the sun as a guide. Birds that migrate at night use the stars to know where they are. There are even more complex ways that animals navigate. I hope this helps you understand animal migration. There are so many more interesting things you can learn about it too. Follow these links to learn more

4 Name: Student Response Worksheet (Lower) 1. What migratory bird did Amy and Dave see for the first time this week? 2. Loons are returning to the Boundary Waters after spending winter in a climate. 3. Some animals travel a way when they migrate, others don t travel far at all. 4. When all members of a species move it is called a migration. 5. The most important reason for migration is. Bonus: Describe in detail how different loons look between summer and winter.

5 Name: Answer Student Response Worksheet (Lower) 1. What migratory bird did Amy and Dave see for the first time this week? loon 2. Loons are returning to the Boundary Waters after spending winter in a southern climate. 3. Some animals travel a long way when they migrate, others don t travel far at all. 4. When all members of a species move it is called a _total migration. 5. The most important reason for migration is food. Bonus: Describe in detail how different loons look between summer and winter. When the loons headed south for the winter, they were mostly gray. Now the loons have their summer plumage, which is a black head, black back with white spots, and white belly.

6 Name: Student Response Worksheet (Upper) 1. Name three lakes mentioned in this week s Notes. 2. What direction do animals generally migrate in the United States in the fall? 3. Describe the difference between partial and complete migration. 4. What is it called when a group of animals migrate together? 5. Describe why scientists thought loons were actually two different species. Bonus: If you could migrate each winter, where would you go, and why?

7 Name: Answer Student Response Worksheet (Upper) 6. Name three lakes mentioned in this week s Notes. Knife, Bonnie and Spoon 7. What direction do animals generally migrate in the United States in the fall? South 8. Describe the difference between partial and complete migration. In partial migration only some members of a species migrate. In complete migration all members of a species migrate. 9. What is it called when a group of animals migrate together? nomadic migration 10. Describe why scientists thought loons were actually two different species. because they looked very different between summer and winter when they were seen in different places._ Bonus: If you could migrate each winter, where would you go, and why? Answers will vary