As a result , the genetic code of mallards in Europe now contains significant DNA from the disappearing black duck .
For example , the North American black duck is being gradually subsumed and eliminated by interbreeding with the European mallard , Trinkaus said .
The genetic code of mallards in European now contains significant DNA from the disappearing black duck .
For example , the North American black duck is being gradually subsumed and eliminated by interbreeding with the European mallard , Trinkaus said .