Great picture - but most duck hunters would fail to see the hybrid

The top, middle male is a hybrid between a Scaup and a Ring-necked Duck. No surprise, most hunters miss them even in the bag!

While rare, hybrids are regular in ducks with broadly overlapping ranges.  Historically the "best guess" for fairly frequent hybridization was brood parasitism, but genetic data that identified hybrid sires rejected this idea.  Instead, wrong-species rapes is the winning explanation! 

Now who do you suppose most frequently sires Mallard x Pintail hybrids??