Animals on the move

Here is a movie of migrating geese.
Video and image courtesy of Ducks Unlimited Canada

A flock of geese flies gracefully overhead. You wish you could see the world as they see it. You wish you could fly and be as free as they are. You wonder where they are going in such a hurry!

Well, don't envy them too much, because they may be on a very long, tiring journey. Many geese and other birds migrate thousands of miles every year. Some travel over 7,000 miles one way! Some may travel up to 1000 miles without even a rest stop, crossing the Gulf of Mexico or the Sahara Desert.

These birds must follow their food supply and they must return to certain locations to breed.

They migrate to survive!

Besides birds, some other long-distance travelers are fish, sea turtles, bears, caribou, whales, and porpoises. Some of these kinds of animals are shrinking in population. Some are in danger of disappearing forever. Scientists want to know what is happening to them and why. As part of the answer, they want to know where the animals go, how they get there, and how long they stay.

A good way to learn about animals is to track them from space. Scientists pick individual animals and fit them with lightweight, comfortable radio transmitters. Signals from the transmitters are received by special instruments on certain satellites as they pass overhead. These satellites are operated by the National Oceanic and Atmospheric Administration (NOAA). The polar orbits of the satellites let them see nearly every part of Earth as it rotates below and receive signals from thousands of migrating animals. You can find out more about this kind of orbit.

Diagram of satellite tracking of migrating animals. After the satellite gets the signal from the animal's transmitter, it relays the information to a ground station. The ground station then sends the information to NASA's Goddard Space Flight Center in Maryland. Goddard then sends the information about the animal to the scientists, wherever they may be.