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| Wild Pacific salmon live along river systems that cross international borders and fall under various jurisdictions, so keeping track of their habitat is a challenge. |
This year marks 500 years since the first crossing of the Pacific (Ferdinand Magellan) and 1,000 years since the first trek of the Atlantic (Vikings), but on long-distance travel, animals have always had us beat.
Animal migrations cover unbelievable distances, and it's not just birds flying south to find warmer climates. All kinds of animals migrate, from whales to butterflies, and new technologies are teaching us much more about the amazing journeys they take.
Animals migrate for several reasons. One is to find food. In regions of Africa, for example, zebras and other animals are constantly on the move to find grass and water.
Some whales travel for food too. They swim to icy waters in the north to find fish, and return south in winter to raise their young.
Other animals migrate for better weather—south for the winter and north for the summer (in the Northern Hemisphere). Both Canadian geese and monarch butterflies migrate each year between Canada and Mexico—traveling thousands of
kilometers.
One other reason animals migrate is for reproduction. Perhaps best known for this is salmon. Born in rivers often high in mountains, these fish migrate from freshwater rivers to the sea, where they feed and grow. Incredibly, after as long as seven years, salmon swim back up the rivers they came from in an incredible show of swimming against the current—to reproduce where they were hatched.
What are the longest journeys made by migrating animals? The bar-tailed godwit may take the record for that, and technology allows us to track them.
These birds reproduce in Alaska and migrate south all the way to New Zealand. They cross the Pacific Ocean north to south traveling more than 11,600 kilometers in a nonstop flight that lasts for nine days.
Monarch butterflies have multigenerational travels. Each autumn more than 100 million of the butterflies head south, traveling up to 4,750 kilometers.
The distance south and back is so long, no single butterfly completes the journey. The females lay eggs along the way and the next generation continues the migration.
How do animals navigate while traveling so far? For some, sight is important. They can remember the land, sunlight, and even stars.
For others, smell and taste are key. Salmon locate the rivers they were hatched in by tasting the minerals in water.
Technology is helping us learn more about animal migrations. The more we learn, the more we see how amazing animal migrations are.
By John Sailors
Off Key Blog, 10/22/21
Copyright 2021, by John Sailors.
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