Animal Migration: Top 10 Questions
Thanks to Jeff Knetter, upland game and waterfowl staff biologist, Idaho Department of Fish and Game; and Vicky Runnoe, conservation educator, Idaho Department of Fish and Game for the answers.
1: Why does migration happen?
Migration is the movement from a place an animal lives to a place that provides something that it needs. So, if a food source disappears because of winter weather, an animal may leave to find food someplace else. They can come back. Food is the main reason for migration. (From Joe in Mrs. Schweitzer's class at Riverside Elementary School in Boise)
2: If mammals are warm, why do they migrate?
Many animals migrate for food, not warmth. Mule deer or elk, which may summer at a higher elevation, will move to a lower elevation or a different aspect of slope so they can access vegetation more easily. (From Maddie in Jan McCamish-Cameron's class at Grace Jordan Elementary School in Boise)
3: How do animals know when to migrate?
Animals and humans have a special gland in their brains that tells them when the light is changing. As the days get shorter and there is less light in winter, animals sense this and get what is called migratory restlessness. It lets them know, gosh, it's time to get out of here. (From Luke in Mrs. Schweitzer's class at Riverside Elementary School in Boise)
4: How long does it take to migrate?
It all depends on the species and the type of winter. If it's a mild winter, animals like deer or elk will not have to travel as far as they do when it's a more severe winter. Steelhead and Chinook salmon take months to cover the ground they have to cover. In addition, some birds take weeks to migrate and some only take a few days. (From Joe in Mrs. Woodall's class at Dalton Elementary School in Coeur d'Alene)
5: Do whales migrate?
They do. They will move from summering grounds, where there's a lot of krill for them to eat, to other areas where they can find their food. In February, you can find the humpback whale in Hawaii. Then it heads north to the Arctic for the summer where there is a lot of food for it to eat. Even a big animal living in the ocean will migrate to find the food it needs. (From Morgan in Mrs. Hunt's class at Cynthia Mann Elementary School in Boise)
6: What do animals do when they are migrating?
They are moving for the most part. Birds and mammals move across the landscape, taking time to rest. They also need to eat and drink water to make sure they have the energy to reach their destination. (From Gabe in Jan McCamish-Cameron's class at Grace Jordan Elementary School in Boise)
7: Why do birds fly south? Do they fly other ways?
They do. Some birds do not have to fly south to get to the place where they find food. The Northern Wheatear is one example of this where they nest in Alaska and fly south and west to end up in Africa. Birds will fly in a direction that's going to take them to the habitat they need for the winter and then they head back for the summer. (From Gurum in Jan McCamish-Cameron's class at Grace Jordan Elementary School in Boise)
8: How far can a bird fly without stopping?
Some birds, like the Ruby Throated Hummingbird, will fly all the way across the Gulf of Mexico without stopping. Birds have been recorded flying two full days, or 48 hours, before they'll touch down. They need to have a lot of energy to make these long trips! (From Bridgette in Mrs. Hudson's class at Dalton Elementary School in Coeur d'Alene)
9: Do animals, like fish and caribou, travel together to migrate?
I'm not aware of any that do other than waterfowl, which migrate together (like ducks and geese). Then there are species that travel in herds, like deer and elk. (From Alexa in Mrs. Adcock's class at Hillview Elementary School in Ammon)
10: Animals don't have GPS, so how do they know where they are going?
Animals may use sun or light to help them migrate. Also landmarks can help them, like rivers or forests. If they are traveling at night, they may be guided by the stars or by the pull of the magnetic poles on the earth. Animals use many things to help them know where they are and where they are going. (From Cassie in Mrs. Woodall's class at Dalton Elementary School in Coeur d'Alene)
Click on a Topic:
- Ages Past
- Earth Science
- Human Body
- Science Fundamentals