Birds with extra wings in Welsh port (7)
I believe the answer is:
swansea
'welsh port' is the definition.
(I've seen this in another clue)
'birds with extra wings' is the wordplay.
'birds' becomes 'swans' (swan is a kind of bird).
'with' is a charade indicator (letters next to each other).
'wings' means to remove the middle letters (the wings or edge letters of the word are used).
'extra' with its middle removed is 'ea'.
'swans'+'ea'='SWANSEA'
'in' acts as a link.
(Other definitions for swansea that I've seen before include "Ecstasy, a win! (anag)" , "Home of the DVLA" , "South Wales city" , "coastal location" , "Second city of Wales" .)