South American sea lion vs fur seal

South American sea lion

noun
  • A sea lion, Otaria flavescens, found on the Chilean, Peruvian, Uruguayan and Argentine coasts, with a very large head with an upturned snout. 

fur seal

noun
  • A marine mammal of either of the genera Arctocephalus or Callorhinus of the eared seal family Otariidae, differing from the sea lions in having dense underfur. 

How often have the words South American sea lion and fur seal occurred in a corpus of books? (source: Google Ngram Viewer )