Expert: Roger Lederer - 8/28/2008

Question
Dear Dr. Lederer -

I noticed a long time ago while a student in the University of Iowa (in Iowa City, not Iowa State) that a group of wild mallards who lived around the college city's riverbanks would sometimes "gang murder" a duck. I witnessed this more than once and it disturbed many onlooking students like myself. One poor duck would be pecked at and nipped at by a huge flock of ducks and killed in the process. To make sure it was dead, the duck would be nipped over and over in the eye area by other ducks hovering over it.

Please tell me what was going on and why this happens. It's been 14 years since I was an undergrad but the memory remains fresh as I am really curious to know what the cause of this behavior is coming from.

Looking forward to hearing back from you!  

Answer
Well, I can't give you the exact reason because I don't know the exact circumstances. But I presume that the ducks were in a suburban/urban area as there were many human witnesses. In an artificial environment like that, strange things happen. This does not happen in the wild. It could be that the duck was a hybrid of mallard/pintail or mallard/muscovy or some other strange hybrid. Or it could be that the duck was a wild duck and all the others were domestic. Domestic situations lead to strangeness.