Big bird needing some bigger nest (4)
I believe the answer is:
erne
'big bird' is the definition.
'erne' can be an answer for 'bird' (erne is a type of bird). I am not sure about the 'big' bit.
'some bigger nest' is the wordplay.
'some' indicates the answer is hidden within the clue (some parts of the word are used).
'ERNE' can be found hidden inside 'bigger nest'.
'needing' acts as a link.
Can you help me to learn more?
(Other definitions for erne that I've seen before include "Fish-eating sea eagle" , "Island-studded lake in Fermanagh" , "Irish lough" , "Sea bird: lough in Ulster" , "'Sea-eagle, river and lough (4)'" .)