Historian E. L. Joseph claimed that Trinidad's Amerindian name was ''Cairi'' or "Land of the Humming Bird", derived from the Arawak name for hummingbird, ''ierèttê'' or ''yerettê''. However, other authors dispute this etymology with some claiming that ''cairi'' does not mean hummingbird (''tukusi'' or ''tucuchi'' being suggested as the correct word) and some claiming that ''kairi'', or ''iere'', simply means ''island''. Christopher Columbus renamed it "La Isla de la Trinidad" ("The Island of the Trinity"), fulfilling a vow made before setting out on his third voyage of exploration. Tobago's cigar-like shape, or the use of tobacco by the native people, may have given it its Spanish name (''cabaco'', ''tavaco'', ''tobacco'') and possibly some of its other Amerindian names, such as ''Aloubaéra'' (black conch) and ''Urupaina'' (big snail), although the English pronunciation is .