heron vs white stork

heron

noun
  • A long-legged, long-necked wading bird of the family Ardeidae. 

white stork

noun
  • A large wading bird, Ciconia ciconia, that winters in Africa and breeds in Europe; in European folklore, it delivers babies. 

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