redstart vs rufous-tailed scrub robin

redstart

noun
  • A not closely related species of warbler native to the Americas, Setophaga ruticilla 

  • Any of various insectivorous ground-feeding birds, mainly of the genus Phoenicurus. Many of the species have a red tail. 

rufous-tailed scrub robin

noun
  • Cercotrichas galactotes, a species of bird. Also called rufous scrub robin, rufous bush robin, rufous warbler, rufous bush chat 

How often have the words redstart and rufous-tailed scrub robin occurred in a corpus of books? (source: Google Ngram Viewer )