Part 1: Which way to the beach?
Brrr! When it gets cold outside, people bundle up in big coats and often stay inside their warm, cozy houses... But I've often wondered: How do animals survive the long, cold winter?Over a cup of hot chocolate, Henrietta helped me discover one of the things animals can do to survive winter.
Migration
Do your grandparents go to Florida when the weather gets cold? Many different types of animals do the same thing, and "migrate" (travel) somewhere warmer in winter.
Some birds migrate - either in flocks (groups) or alone. Birds can travel great distances, for example, every fall, the Arctic Tern travels all the way to the Antarctic, and every spring, it travels back up to the Arctic again!
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| Arctic Terns preparing to go south for the winter |
How do birds know when to leave and where to go? A combination of changes in the weather, the amount of daylight and the food available helps the birds decide when to leave. Birds amazingly find their way using the sun, moon, stars and even smell to guide them. They also seem to have a "compass" in their brain that allows them use the Earth's magnetic field.
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| Modern goose migration |
Some insects migrate too - Monarch butterflies spend summer in Canada and the Northern US, and in winter, they go to Mexico. (Even though they don't need to, many people in Canada do the same thing!)
Other insects, such as termites and ants, migrate short distances by moving deeper into their underground colonies to escape the frosty world above.
Some fish do the same thing, and move to deeper water in winter. Other fish may swim south.
Finally, a few mammals (such as elk, caribou and bats) migrate in winter to search for food.
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| Caribou deciding it's time to migrate for the winter |
Not all animals migrate, so stay tuned for more frosty animal facts! I think I need another sweater...
Nice to meet you Quentin and Henrietta!
ReplyDeleteI've always wondered how animals figure out how to return North to the same place every year? Aside from your Canada goose using his smart phone, do Quentin and Henrietta have any ideas?
ReplyDeleteGreat question Clarissa!
ReplyDeleteAnimals have all kinds of ways of knowing where to migrate and how to find their way back again.
Some animals use sight to guide them. They may look at the landscape, or look at the way the sunlight reflects on air particles, so they can find their way even on cloudy days. At night, they follow the stars.
Animals can use other senses too. Migrating salmon "taste" the concentration of minerals in the water to guide them back to the spot where they were born.
Some animals can even sense the Earth's magnetic field. The Earth acts like a giant magnet, with magnetic forces running between the North and South poles. Humans can't feel these forces, but many animals can, and they use this to guide them.
Some migrants even do it the easy way - they just go with the flow! For example, some turtles let the ocean currents (natural flow of water) to carry them to the right spot.
Here's a great place to learn more:
http://www.nature.com/scitable/knowledge/library/animal-migration-13259533
- Henrietta
Dave would like to ask Quentin and Henrietta where the dead leaves go during the winter. They are on the ground during the fall and then there are not there anymore when the snow melts. Any ideas?
ReplyDeleteAnother good question! I think I will write a post about this one after talking to Henrietta, so check back soon!
ReplyDelete