pecking order vs succession

pecking order

noun
  • The usually informal hierarchy of authority or command, often partial or approximate, as determined by the especially natural propensity for domination of different members of a specific group over each other, such as older brothers and sisters over their younger siblings. 

  • The natural hierarchy of social status and dominance occurring in a group of birds. 

succession

noun
  • In Roman and Scots law, the taking of property by one person in place of another. 

  • An act of following in sequence. 

  • A group of rocks or strata that succeed one another in chronological order. 

  • A right to take possession. 

  • A race or series of descendants. 

  • A sequence of things in order. 

  • A passing of royal powers. 

  • Rotation, as of crops. 

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