Massive animal migrations are among nature’s most inspiring events. Whether by wing, fin, or hoof, the distance some creatures travel in search of new habitat is paralleled only by what they endure.
Migrations also play a vital role in our natural ecosystems — they are the veins and arteries of Mother Earth — and they are a reminder that the world’s habitats are interconnected. Here’s our list of the planet’s greatest migrations.
These charismatic ocean wanderers make incredible migrations in the open sea to feed, mature, and lay eggs.
Scientists have recorded some leatherback turtles traveling across the Pacific Ocean between Indonesia and the west coast of the United States and Canada, which totals more than more than 10,000 miles. One of their most impressive feats is navigating back to the beach where they were born to spawn. A loggerhead sea turtle named Yoshi swam 22,000 miles over two years. Two Oceans Aquarium staff released Yoshi after a 20-year residency. She originally went to the aquarium because of a cracked shell.
Gray whale breaching off the Oregon coast
Merrill Gosho, NOAA / Wikimedia Commons / Public Domain
While many of the world’s marine mammals migrate, none go the distance like giant baleen whales. One species of baleen whale, the gray whale, makes a 10,000- to 14,000-mile round trip on its annual migratory journey.
Each species travels to warmer tropical waters during the winter months to mate and give birth. Then they swim to the rich colder waters of the Arctic or Antarctic to feed for the summer. Climate change and warmer surface temperatures have altered the timing of that migration, and it may not be sustainable.
Dragonflies are capable of long-distance migrations, but until 2009 scientists had no idea how far they traveled. Scientists discovered a 14,000- to 18,000-kilometer dragonfly migration route that spanned from India to the Maldives, Seychelles, Mozambique, Uganda, and back again. One tiny species has a flying range of 4,400 miles or more over open ocean waters.
Incredibly, the epic migration spans four generations of dragonflies, with each generation playing its part in the journey, much like a relay race. It is easily the longest insect migration ever discovered. The dragonflies appear to follow the rains, from the monsoon season in India to the rainy season in eastern and southern Africa.
Perhaps the most visible animal migration is the journey of Africa’s wildebeest herds, which travel annually by the millions in search of greener pastures. Millions of wildebeests suddenly start migrating at the same time each year.
The migration is one of nature’s grandest spectacles, as the herds cross crocodile-infested rivers while lions prowl in the tall grass nearby. Over 250,000 wildebeests fall victim to hungry predators and the other perils of migratory travel, such as drowning, starvation, and disease, along the way.
Africa’s vast savanna could not exist without the migration, and maintaining these habitat corridors is essential to the survival of this area and its creatures.
About 4,000 species of birds are regular migrators. Some of these journeys are among the longest in the world.
The tiny Arctic tern makes the world’s longest migration annually as it zigzags 55,923 miles between the Arctic and Antarctic. An honorable mention goes to the sooty sheerwater for making a similar journey. Bar-tailed godwits undertake the longest nonstop flight of any bird, 6,835 miles in nine days, between New Zealand and China.
Penguins also migrate, sometimes due to the effects of climate change. They deserve credit for making their journey through the ocean and by foot instead of by air. Adélie penguins make the longest migrations, with one penguin migrating more than 10,936 miles, according to researchers using tracking devices.
The annual monarch butterfly migration spans 3,000 miles and might be the most colorful migration in the natural world. The farthest tracked monarch flew 265 miles in one day. The monarch migration includes three to four generations and occasionally crosses the Atlantic Ocean.
Monarchs also live in Australia and New Zealand, where they are called wanderer butterflies.
North America’s caribou populations migrate the farthest of any terrestrial mammal, a journey that can span more than 838 miles annually. This distance is significantly lower than the 3,000-mile distance scientists used in the past. Part of that reduction is due to improved data from GPS tracking, and unfortunately, the rest is due to climate change, which is also changing the timing of migration.
Herds of the migrating animals can grow to impressive numbers — with 197,000 members of the Porcupine caribou herd — rivaled only by Africa’s great wildebeest migrations. During the winter, caribou travel to forested areas for easier foraging, and they migrate in the summer to superior calving grounds.
Salmon impressively travel hundreds of miles in inland freshwaters and up to 1,000 miles in the ocean during their migration to feeding grounds. On their return to their breeding grounds, they will even ascend thousands of feet up mountain streams.
They do all of that navigation primarily through using the earth’s magnetic field as a compass. When they get close to spawning areas, they use their sense of smell to find their way home.
Zooplankton, organisms such as diatoms and krill that float in the ocean column, seem like unlikely migratory animals. Their migration is different because it moves up and down through the ocean’s depths rather than traversing a landscape, although they can do this, too. The movement of zooplankton, known as vertical migration, rivals the seasonal migration of more famous migratory species such as caribou or Arctic tern.
Despite their tiny size, some zooplankton swarms swim a vertical distance of 3,000 feet nearly every day in their continual search for food.
Although not all bat species are migratory, the ones that travel seasonally do so in spectacular fashion. The world’s most massive mammal migration is the annual journey of Zambia’s straw-colored fruit bats. An astounding 10 million bats blanket the air during the migration, as they travel to feed on their favorite fruits in the mushitu swamp forest.
Christmas Island Red Crabs
One of the most incredible migrations is the seasonal movement of the red crab across Australia’s Christmas Island.
More than 120 million red crabs call this remote island home, and every year they transform the island into a vast moving red carpet as they move en masse to the ocean to lay their eggs.
During periods of peak migration, Christmas Island’s roads often must be closed as the crabs blanket the landscape. Scientists have recently discovered that hormonal changes cue the crabs to undertake their arduous journey.
Some shark species travel thousands of miles through open water every year, scouring the ocean for food. Other sharks have a daily vertical migration from deeper water to shallower water in search of food or to warm up.
The great white shark is a long-distance traveler, with some making the journey across the Indian Ocean between South Africa and Australia and back again during a single year.
The larger but more gentle whale shark is another known migrant, with one undertaking a 12,000-mile migration. The migration of the endangered whale shark between the Eastern Pacific and Western Indo-Pacific makes conservation activities more complicated as more jurisdictions are involved.
Other migratory sharks are giving up annual migrations as the water stays warm due to climate change.
Tuna are among the ocean’s fastest swimming migratory fish. They swim across such large distances, including between oceans, that fishing regulations have failed to adequately protect them from overfishing. The IUCN lists Atlantic bluefin tuna as endangered, southern bluefin as critically endangered, albacore as near threatened, and Pacific bluefin as vulnerable. Only skipjack tuna has a stable population.
Seals migrate long distances in order to find food. Fur seals swim the equivalent of a quarter of the way around the world every year. Bull elephant seals make a annual migratory journey of at least 13,000 miles and spend about 250 days during that time at sea. Females spend an incredible 300 days at sea each year. Elephant seals have two separate annual migrations: one after breeding season and one after molting season.