Congratulations on a fine fall bird and a large concentration of birds. Is this the high point on your birds population cycle or do you run about this many birds all the time? We have cycles in populations here on the Ms. River. Our populations cycle up like yours when the River stays low and the spring rises do not get the hatch. At these times we will have a 100 or so in a flock. When the population gets high, I have seen the numbers wiped out by foul pox and blackhead. I have seen this happen twice in about 35 years.