Enlarge / This drake mallard duck has ceased to be! And suffered one final post-mortem ignominy by a fellow duck. (credit: C.W. Moeliker, 2001) On June 5, 1995, a Dutch ornithologist named Kees Moeliker was working quietly in his office in the new wing of the Natural History Museum in Rotterdam, the Netherlands, when there was an unusually loud bang one floor below.