curlew vs whimbrel

curlew

noun
  • Any of several migratory wading birds in the genus Numenius of the family Scolopacidae, remarkable for their long, slender, downcurved bills. 

  • A stone curlew. 

whimbrel

noun
  • A large migratory wading bird, Numenius phaeopus, of the family Scolopacidae, with a long downcurved bill. 

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