Today is the centenary of the extinction of the passenger pigeon. The very last bird (Martha, after Martha Washington) died in the Cincinnati Zoo on September 1, 1914. It was, without doubt, the most dramatic extinction ever witnessed.
"The number of these birds … was far beyond the power of human calculation," wrote Virginia historian Philip Bruce in the 17th century. With awe, he recorded that, "for hours they darkened the sky like a pall of thunder clouds; and that they broke down, by their weight, the limbs of the forest whenever a entire flock lighted in search of food."