aurochs vs wisent

aurochs

noun
  • The European bison (Bison bonasus, or Europæus). 

  • An extinct European mammal, Bos primigenius, the ancestor of domestic cattle. 

wisent

noun
  • The European bison, Bison bonasus. 

How often have the words aurochs and wisent occurred in a corpus of books? (source: Google Ngram Viewer )