least weasel vs mustela

least weasel

noun
  • The common weasel, little weasel, or simply weasel (Mustela nivalis), the smallest member of the weasel genus Mustela, native to Eurasia, North America, and North Africa. 

mustela

noun
  • Any of the carnivorous mammals of the genus Mustela. 

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