Shore bird in difficulty (4)
I believe the answer is:
knot
I believe this is a double definition.
'shore bird' is the first definition.
(knot is a kind of shore bird)
'difficulty' is the second definition.
(I've seen this before)
'in' is the link.
(Other definitions for knot that I've seen before include "Something tied" , "Ring < sandpiper" , "Small cluster - huddled group - sheepshank, for example" , "Bird; hard part in wood" , "Measure of speed at sea" .)