eagle owl vs little owl

eagle owl

noun
  • Any of various Old World large owls of the genus Bubo, especially the Eurasian eagle owl, Bubo bubo, that have prominent ear tufts. 

little owl

noun
  • A species of small European owl, Athene noctua. 

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