Rapacious seabird (4)
I believe the answer is:
skua
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">rapacious seabird</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 skua that I've seen before include "Predatory northern seabird" , "Flyer" , "Large brown seabird" , "Large sea bird" , "Auks (anag.)" .)