Rounded Rectangular Callout: Distal HalfRounded Rectangular Callout: Basal Half Rounded Rectangular Callout: Undertail CovertsRounded Rectangular Callout: Vent CovertsThe terms “basal” & “distal” does not refer to any coloration seen; they refer to different areas
of the feathers; basal (quill tip to about half way out towards the feather tip end) & distal (from the
feather tip end to about half way towards the rump). The tail bar is the dark (black) colored area in
the “basal half” of the feathers in this picture. Tail bars are typically always horizontally across the
width of the entire tail and can be positioned anywhere in the tail (topside or underside), vary in
number, coloration & thickness depending on species.