I have 9 female ducks, 1 male duck, and 2 unsexed chinese geese, all 13 weeks old, from Metzer Farms. A few weeks ago I caught the White Chinese goose pinning down the female Black Indian Runner in the water, until it seemed like she was drowning. Today I heard a bunch of quaking, and my Brown Chinese Goose had the black Runner by the neck, and was thrashing her around. I ran in the pen and had to take the goose off the duck. After they were seperated the goose kept on choking on all the feathers it had pulled out. The duck does not seem to be lowest in the pecking order, she is always one of the first to the food and in the pool. I have seen no other agresion in this flock, just between the geese and the black Runner I really don't understand it, why are they doing this? Is there anyway to get them to stop? Thanks, I appriceate it.