pecking order vs series

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. 

series

noun
  • A subdivision of a genus, a taxonomic rank below that of section (and subsection) but above that of species. 

  • A set of consonants that share a particular phonetic or phonological feature. 

  • A television or radio program which consists of several episodes that are broadcast in regular intervals 

  • A number of things that follow on one after the other or are connected one after the other. 

  • An unranked taxon. 

  • A parcel of rough diamonds of assorted qualities. 

  • The sequence of partial sums ∑ᵢ₌₁ⁿa_i of a given sequence aᵢ. 

  • A group of matches between two sides, with the aim being to win more matches than the opposition. 

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