white drummer
... that the call of the white drummer is amplified by its sac-like tympal covers?
... that the call of the <b id="mwBtE"><a href="./Arunta_perulata" id="mwBtI" rel="mw:WikiLink" title="Arunta perulata">white drummer</a></b> is amplified by its sac-like tympal covers?