down feather vs vibrissa

down feather

noun
  • A feather of the down of a bird 

vibrissa

noun
  • Any similar feather near the mouth of some birds. 

  • The thick hairs found inside the nostrils of humans and other mammals. 

  • Any of the tactile whiskers on the nose of an animal such as a cat. 

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