The DNA of the extinct passenger pigeon reveals a complicated history

Carl Zimmer in his excellent blog, The Loom:

In the early 1800s, a naturalist named Alexander Wilson was traveling in Kentucky when the sky suddenly became dark. Wilson believed, he later wrote, that it was “a tornado, about to overwhelm the house and everything round in destruction.”

When Wilson got his wits back, he realized the sun had been blotted out by passenger pigeons.

The journals of many early explorers contain similar passages. The passenger pigeon would sweep across the eastern United States in vast flocks, feeding on chestnuts and acorns as they traveled. As Wilson gazed at his passenger pigeon flock, he tried to figure out how many birds it contained. From one side to the other, it was a mile wide. It streamed overhead like a feathered river for more than four hours. Based on that information, Wilson guessed that it contained over 2.2 billion birds–”an almost inconceivable multitude,” he wrote, “and yet probably far below the actual amount.”

In 1914, the passenger pigeon became extinct, likely thanks to industrial-scale hunting. In his book Nature’s Ghosts, Mark Barrow notes that our eradication of such a populous species came as a tremendous shock–one that helped the world appreciate nature’s true fragility.

More here.