Likelyhood of a bird moving fish is very low probability, but I suppose not impossible. I have two ponds that were stocked 3 and 10 yrs ago. One pond has just shiners and other pond has just primarily yellow perch and 3 species of forage fish. Both ponds are within 60-90 ft of a creek. After routinely sampling these ponds, I have no other fish in the ponds besides the ones that were originally stocked. I received a call today from a guy that was developing a panfish only pond. Neighbor kids told him they stocked some bass in his pond; that is where most fish contamination comes from - "do gooders" - human sources and human errors.


aka Pond Doctor & Dr. Perca Read Pond Boss Magazine -
America's Journal of Pond Management