posturing vs shrouding

posturing

noun
  • The behaviour of some birds as a means of signalling etc. 

  • The assumption of an exaggerated pose or attitude. 

shrouding

noun
  • A shroud (annular plate at the periphery of a water wheel, forming side of bucket). 

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