black-headed gull vs lesser black-backed gull

black-headed gull

noun
  • A small gull, Chroicocephalus ridibundus, which breeds in much of Europe and Asia, and also in coastal eastern Canada. 

lesser black-backed gull

noun
  • a seabird and member of the gull family, genus Larus fuscus 

How often have the words black-headed gull and lesser black-backed gull occurred in a corpus of books? (source: Google Ngram Viewer )