It's likely we're mostly to blame. Apparently Rocky Mountain locusts laid their eggs in a relatively small area of land when they weren't swarming that we plow

It's likely we're mostly to blame. Apparently Rocky Mountain locusts laid their eggs in a relatively small area of land when they weren't swarming that we plowed up, destroying all the egg cases. From the wikipedia link elsewhere in this thread, it's claimed that hundreds of cases were destroyed per square inch of land by farming. In the case of passenger pigeon, I've seen evidence that they did have booms and busts historically, but we slaughtered them for food, feed, and fun in truly staggering numbers [1] There was a massive passenger-pigeon-harvesting industry that was interested in harvesting as many birds as possible until there weren't any left. [1] As many as a billion birds were killed by hunters in a single 50 day hunt near one Michigan town. http://www.detroitnews.com/article/20120318/METRO/203180301 http://www.detroitnews.com/article/20120318/METRO/203180301