Not quite by accident. The treaty recognized that Norte Americanos were going to utilize their shotguns to thin out crows. My understanding is that the treaty permitted shoting crows during established seasons and apparently left a loophole for controling crop predation. By way of disclaimer, most of what I have related is simply what I was told, but I do know that crow seasons were established and shooting magpies became an absolute no no [when there had been a small bounty on magpies only a few years earlier.]