The unique tradition goes back hundreds of years and was initially aimed at feigning a stag's rival during the rutting season so the deer comes out.

DORTMUND, Germany (AP) — German hunters tried to convince the jury at a national stag calling championship that they can imitate a bellowing red deer most ... with closed eyes to make sure ...

They are not strictly speaking albinos. Albinos have characteristically red eyes, but deer with leucism have normal colouring in their eyes. A White Stag was the symbol of King Richard ll.