They produce 1 to 1-1/2 lbs of waste per bird, per day. So when you start getting larger flocks they can really mess up a place.

Then you have to get these guys involved. http://www.nebraskagoosepatrol.com/

The larger parks around here get enough dog traffic that you normally don't see many around. Occasionally, you see some without a foot or leg. Those wintered here and survived being frozen into a local pond.