birder vs environmentalist

birder

noun
  • A birdwatcher. 

  • A person who hunts birds. 

environmentalist

adj
  • Of, or relating to environmentalism. 

noun
  • One who holds the view that environment, rather than heredity or culture, is the primary factor in the development of an individual or group. 

  • One who advocates for the protection of the environment and biosphere from misuse from human activity through such measures as ecosystem protection, waste reduction and pollution prevention. 

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