When pioneering Europeans colonised North America, they naturally named the creatures they encountered. And equally naturally, they named them after familiar birds from the European homeland. The diverse, little streaky emberizine bunting-like birds looked a bit like ‘real’ sparrows and the name stuck. The common icterids were mid-sized and black, so became ‘blackbirds’ and their black and orange or yellow cousins looked somewhat like ‘orioles’. Similarly, the starling like (or Jackdaw-like), longer tailed icterids where somehat like the old-world mynahs of the genus Gracula, and so shared the name grackle.
The little colourful thin billed passerines were somewhat like Old World warblers, so became warblers.
And, of course, the large abundant red-breasted thrush, which appeared to occupy the niches of the European Blackbird was called Robin after our familiar little redbreast.
The next time a fellow birdwatcher makes a fuss about calling a bird Bearded Tit (not a ‘real’ tit), Honey Buzzard (not a ‘real’ buzzard) or Hedgesparrow (not a ‘real’ sparrow), gently point out that the inconsistencies and repeated use of the same names for unrelated birds are extremely common, especially in North America.