On Sunday, National Geographic launched a new series on animal migrations. I didn't get to watch the inaugural show (I'm sure I'll catch a rerun later this week), but I did get a chance to read the Great Migrations feature in this month's magazine. It's really a bit humbling to think about the great distances that so many species travel successfully—and repeatedly—guided by instinct and determination. As biologist Hugh Dingle is quoted:
These critters are hell-for-leather, flat-out just gonna get there.
Dingle identified five characteristics that mark animal migrations, which include
- prolonged movement outside normal zones of habitation
- a linear path
- special preparatory behaviors such as overfeeding
- accumulation of special energy reserves for the trip
- dedication to the trip without wavering
These traits can occur in varying degrees in any migration—even “minor” excursions can be important enough to warrant preparation. For example:
(D)aily vertical movements by zooplankton in the ocean—upward by night to seek food, downward by day to escape predators—can also be considered migration. So can the movement of aphids when, having depleted the young leaves on one food plant, their offspring then fly onward to a different host plant, with no one aphid ever returning to where it started.
I witness and participate in a migration on a daily basis: my commute to and from work. Seriously—as I watched my fellow commuters at Penn flow around me last week when I stopped to listen to a busker, it struck me that we exhibit Dingle’s characteristics above:
- The commuter rail systems (LIRR, NJ Transit, and MetroNorth) bring people to New York City from great distances; there are people who travel up to three hours each way to get to and from work in Manhattan.
- Commuters are moved along in great waves of people that are most efficient when they move together linearly as a group. As a result “corridors” of travel emerge where people move in streams (see video below).
- Many commuters purchase snacks for the ride home. Or they ensure that their electronic devices are charged for the ride, enabling them to listen to music or read digital books.
- Commuters often travel with caffeinated beverages or other forms of refreshment. They will nap on the trains as if recharging for the next leg of their journey which may require them to navigate a subway or operate a vehicle.
- Commuters are fixed on their destination particularly when it is homeward bound. When the LIRR experienced severe delays a few weeks ago as a result of a tornado that swept through the area, they found alternate means of getting home.
Migratory patterns are everywhere. Groups forced to act in concert will move together. There’s a certain security to it. Animals migrate for better grazing grounds, to survive the season, and for mates and parenting benefits. There is some evidence that suggests our evolutionary cousins the Neanderthals also followed migratory patterns likely for similar reasons. The daily commute moves people from their families to a means of support—sounds like an adaptation to me. Commuting may not have the beauty of sandhill cranes rising in unison, but its purpose is still the same.