DIED the study captured everything in the area of the BG beds thought to prey on BG fry and tested stomach contents. They made no mention of gams or minnows (other than shiners) and so I assume they were not able to prey on BG fry due to male BG nest guarding. That was one of the factors measured also. Gams would be brave indeed if they went into a colonial nest site and crossed the collective male BG , each many times there size when those male BG often see the gams as food. No doubt that there may be some small period of time after BG fry swim up and leave the nest (no male protection) and before the yoy are big enough to fend where gams may eat some and kill others. However in most pond situations the usual BG #s would dwarf the gams #s. Further much of the gams noted attack behavior is based on territorial nature and not on feeding and most noted effects are on minnows and inverts. competing for the same space. I will check some more and see what I find on gam effects on BG yoy.