Plume sources (6)
I believe the answer is:
egrets
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">plume sources</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for egrets that I've seen before include "Greets in way of certain herons (" , "Greets like certain herons" , "Kind of herons with long white feathers" , "White wading birds" , "Fliers" .)