here is a link to an article written about blasting crow roosts near rockford, IL in the 40's. they killed over 300K in one winter averaging approx 11K per nightly blast. the article starts on page 72.
Very informative. I have talked to farmers in north Texas who told stories of setting off dynamite under piles of pea gravel inside of crow roosts. Reading this article and seeing the pictures from Life magazine was a real treat.