geration in the records of such earlier observers as Alexander Wilson, the ornithologist, who said that these birds associated in such prodigious numbers as almost to surpass belief, and that their numbers had no parallel among any other feathered tribes on the face of the earth; or that one of their "roosts" would kill the trees over thousands of acres as completely as if the whole forest had been girdled with an ax.
Audubon estimated that an average flock of these pigeons contained a billion and a quarter of birds, which consumed more than eight and a half million bushels of mast in a day's feeding. They were slain by millions during the middle of the last century, and from one region in Michigan in one year three million Passenger Pigeons were killed for market, while in that roost alone as many more perished because of the barbarous methods of hunting them. They supplied a means of living for thousands of hunters, who devastated their flocks with nets and guns, and even with fire. Yet so vast were their numbers that after thirty years of observation Audubon was able to say that "even in the face of such dreadful havoc nothing but the diminution of our forests can accomplish their decrease."
Many theories have been advanced to account for the disappearance of the wild pigeons, among them that their migration may have been overwhelmed by some cyclonic disturbance of the atmosphere which destroyed their myriads at one blow. The big "nesting" of 1878
