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.

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.

Tracking migrating animals using satellites may help us figure out how to make their journeys as safe as possible and help them survive.

These are some of the animals now being tracked by satellite:

Wood Stork

These are long-legged wading birds. They live in fresh water and coastal marshes in the southeastern United States, Mexico and Central and South America. By tracking four of them using satellites, scientists found that they traveled from their summer breeding grounds at Harris Neck Wildlife Refuge on the Atlantic coast in Georgia to spend winters in southern Georgia and Florida.

Demoiselle Crane

These are the smallest of the cranes, about 3 feet tall. They mate for life. The male courts the female by calling, dancing, and bobbing his head up and down. In the summer breeding season, they are found in Europe from southern Ukraine throughout southeastern Russia, western Siberia, Mongolia and eastern Turkey. For winter, they migrate to northwestern Africa, India and Pakistan.

Siberian Crane

These cranes are the third most rare of all the cranes. They are in danger of disappearing altogether. They migrate from their breeding grounds in extreme northern Russian to southern China or India.

Barrows Goldeneye Duck

This duck lays its eggs in a hole in a tree to keep predators away. Sometimes, the tree is near a lake. Soon after hatching, the mother duck will lead the babies from the nest to the lake. They spend the winter in southern Quebec, in Canada. But where do they go in the winter? A few ducks with transmitters will soon let us know.

King Eider Duck

This beautiful duck is sometimes known as the "comb duck" because its bill looks a little like the comb on a rooster and other birds. This duck breeds in the Canadian Arctic, Alaska, Greenland and Siberia. On the Atlantic coast, it winters south as far as Massachusetts. The duck in this picture is a male, or "drake." The King Eider hen has lovely brown, black, and white feathers, and no "comb" on her bill.

Light-bellied Brent Goose

These geese travel farther each year than any other species of geese, and their journey is the most dangerous. They fly from their winter home in Ireland to the Queen Elizabeth Islands way up north in Canada, a distance of well over 2000 miles!

Tundra Swan

These swans live in Canada. They are very large, weighing 10 to 20 pounds, and they lay very large eggs. Canadian researchers are using satellites to track the birds' 10,000-mile round-trip from their winter home on the Atlantic coast to their breeding ground somewhere in the Canadian Arctic.

Malaysian Elephant

Some of these elephants in Malaysia have caused problems for farmers, so have been moved to other areas away from the farms. Satellites have been used to track where they go. Over one year, they have traveled long distances over a range of nearly 4,500 miles!

Porcupine Caribou

There are more caribou in the Arctic Refuge (in northeastern Alaska and northwestern Canada) than any other large mammals. The Porcupine herd has about 152,000 animals. Scientists are using satellites to understand their migration patterns during the year throughout this huge area.

Deer (in Europe)

Satellites have been used to track deer and other wildlife migrating along the border between Austria and the Czech Republic.

West Indian Manatee

These marine mammals live in rivers, lagoons, and along coastlines of the northwest Atlantic Ocean, from the southeastern United States to Brazil. They are nearly extinct! Scientists have tracked their movements in Belize (in Central America) and in Florida. Understanding their behavior will help wildlife managers to protect them.

Pilot Whale

Whales sometimes come too close to the shore and end up stuck on the sand. If not quickly returned to the sea, they die. Scientists have put satellite transmitters on a few of them before returning them to the sea. The tracking data helped them understand more about the whales' diving behavior and movement. But they still don't understand why whales sometimes beach themselves.

Northern Right Whale

The poor right whales originally got their name because they were the "right" whales to hunt! Humans have hunted them, run them over with their ships, caught them in their fishing nets, and destroyed their habitat. There may be less than 400 of the northern right whales left. They live in the North Pacific and the North Atlantic. They are now being tracked and studied in hopes that we can find a way to protect them from further harm.

Southern Right Whale

This is a different species from the northern right whales. Southern right whales are found in the winter around Australia, South Africa, South America and New Zealand.

Sea Turtle

These animals have been on Earth since before the dinosaurs! But now, humans are hunting them, destroying their habitat, catching them in fishing nets, polluting their waters, hitting them with boats, and otherwise making their lives miserable. Several species are in great danger of becoming extinct. Satellite tracking is helping scientists understand their movements and behavior. They hope to find ways to protect the turtles in the future.

Bluefin Tuna

This fish is among the fastest and biggest. It can weigh up to 1,500 pounds. Over short distances, it can swim as fast as a horse can run. It can swim across the Atlantic Ocean in 40 days. Satellite tracking has found that tuna along the Atlantic Coast of the U.S. migrate to Europe and the Mediterranean to feed.

Walrus

Scientists are studying these large mammals of the seashore in eastern Greenland. Walruses spend about two-thirds of their time in the water. They feed on the sea life in icy areas near the shore. Climate changes cause changes in the ice, which affects the habitat of the walruses. Their populations have been decreasing and scientists want to know why.

Steller Sea Lion

These sea lions live along the shores of the Othotsk Sea (Asia), the Bering Sea (Alaska), and the Gulf of Alaska and along the west coast of Canada and the United States. They are an endangered species. Fish the sea lions eat are becoming scarce because of humans over-fishing these areas. Climate changes may also be reducing the numbers of fish there. With fewer fish to eat, whales may be eating more sea lions instead.

Harbor Porpoise

Harbor porpoises are really whales. They grow to only about five and one-half feet long and weigh about 150 pounds. They can be seen near the coast of Denmark. They are very shy, so are hard to track. A few have been tagged and followed using satellites.