Tens of millions of bison once rumbled across the Great Plains on a quest for grazing. By the late 1800s nearly all had been slaughtered. Today most of the half million remaining bison are in captivity, like these on the Triple U ranch in South Dakota.
Tens of millions of bison once rumbled across the Great Plains on a quest for grazing. By the late 1800s nearly all had been slaughtered. Today most of the half million remaining bison are in captivity, like these on the Triple U ranch in South Dakota.

Animal Migrations

What is it that makes animal migration such a magnificent spectacle for the eye and the mind? Is it the sheer abundance of wildlife in motion? Is it the steep odds to be overcome? Is it the amazing feats of precise navigation? The answer is all of the above. But there’s another reason why the long-distance journeys of wildebeests, sandhill cranes, monarch butterflies, sea turtles, and so many other species inspire our awe. One biologist has noted the “undistractibility” of migrating animals. A nonscientist, risking anthropomorphism, might say: Yes, they have a sense of larger purpose.

Animal migration is a phenomenon far grander and more patterned than animal movement. It represents collective travel with long-deferred rewards. It suggests premeditation and epic willfulness, codified as inherited instinct. A biologist named Hugh Dingle, striving to understand the essence, has identified five characteristics that apply, in varying degrees and combinations, to all migrations. They are prolonged movements that carry animals outside familiar habitats; they tend to be linear, not zigzaggy; they involve special behaviors of preparation (such as overfeeding) and arrival; they demand special allocations of energy. And one more: Migrating animals maintain a fervid attentiveness to the greater mission, which keeps them undistracted by temptations and undeterred by challenges that would turn other animals aside.

An arctic tern on its way from Tierra del Fuego to Alaska, for instance, will ignore a nice smelly herring offered from a bird-watcher's boat in Monterey Bay. Local gulls will dive voraciously for such handouts, while the tern flies on. Why? "Animal migrants do not respond to sensory inputs from resources that would readily elicit responses in other circumstances," is the dry, careful way Dingle describes it. In plainer words: These critters are hell-for-leather, flat-out just gonna get there.Another way, less scientific, would be to say that the arctic tern resists distraction because it is driven at that moment by an instinctive sense of something we humans find admirable: larger purpose.

The arctic tern senses that it can eat later. It can rest later. It can mate later. Right now its implacable focus is the journey; its undivided intent is arrival. Reaching some gravelly coastline in the Arctic, upon which other arctic terns have converged, will serve its larger purpose, as shaped by evolution: finding a place, a time, and a set of circumstances in which it can successfully hatch and rear offspring.

Read This Next

Battle to control America’s ‘most destructive’ species: feral pigs

How coffee can help forests grow faster

The forgotten fossil hunter who transformed Britain’s Jurassic Coast

Go Further

Subscriber Exclusive Content

Why are people so dang obsessed with Mars?

How viruses shape our world

The era of greyhound racing in the U.S. is coming to an end

See how people have imagined life on Mars through history

See how NASA’s new Mars rover will explore the red planet

Why are people so dang obsessed with Mars?

How viruses shape our world

The era of greyhound racing in the U.S. is coming to an end

See how people have imagined life on Mars through history

See how NASA’s new Mars rover will explore the red planet

Why are people so dang obsessed with Mars?

How viruses shape our world

The era of greyhound racing in the U.S. is coming to an end

See how people have imagined life on Mars through history

See how NASA’s new Mars rover will explore the red planet