“A Feathered River Across the Sky”
"Why the passenger pigeon became extinct" explained in a new book of that title reviewed here — The Birds. "How could the bird go from a population of billions to zero in less than fifty years?" An excerpt:
- The passenger pigeon—sometimes called “the blue pigeon,” for its color, though the blue was blended with gray, red, copper, and brown—should not be confused with its distant cousin, the message-bearing carrier pigeon, which is really just a domesticated rock pigeon in military dress. Unlike the rock pigeon—domesticated six thousand years ago, now feral, and brought to these shores by Europeans in the early seventeenth century—the passenger pigeon was native to North America, where it roved over a billion acres of the continent searching for bumper crops of tree nuts. It was here, like the American bison, when Europeans arrived, and it was here when the peoples we consider indigenous migrated across their land bridge thousands of years before that. It evolved on the unspoiled continent and was allied with the big trees that once covered much of the Northeast and the Midwest.
The passenger pigeon was also the most numerous bird species in North America, and possibly the world, dominating the eastern half of the continent in numbers that stagger the imagination. In 1813, John James Audubon saw a flock—if that is what you call an agglomeration of birds moving at sixty miles an hour and obliterating the noonday sun—that was merely the advance guard of a multitude that took three days to pass. Alexander Wilson, the other great bird observer of the time, reckoned that a flock he saw contained 2,230,272,000 individuals. To get your head around just how many passenger pigeons that would mean, consider that there are only about two hundred and sixty million rock pigeons in the world today. You would have to imagine more than eight times the total world population of rock pigeons, all flying at the same time in a connected mass.