Wetland predator (5)
I believe the answer is:
heron
'wetland predator' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for heron that I've seen before include "Grey or white long-legged wading bird" , "Long-legged long-necked wading bird" , "flier" , "Wading bird with long neck and legs" , "eg Egret" .)