"Polioptila nigriceps" . "Chordata" . . . "Aves" . . "Black-capped Gnatcatcher" . "Polioptila" . "Baird 1864" . "Certhiidae" . "Polioptila nigriceps Baird 1864" . "Animalia" . . . . . . . "Passeriformes" . . . . . . . .