An Etymological Dictionary of the German Language/Auerhahn

by Friedrich Kluge

Auerhahn, m., even in MidHG. the equiv. ûrhan (and orhan), m., ‘blackcock,’ with ûrhuon (orhuon), ‘grey hen,’ occurs. Auerhahn was evidently compared with Auerochs, the one appeared to be among the birds of the wood what the other was among animals of the chase.