Bird in spring on river bank (7)
I believe the answer is:
sparrow
'bird' is the definition.
(sparrow is a kind of bird)
'spring on river bank' is the wordplay.
'spring' becomes 'spa' (I've seen this before).
'on' means one lot of letters go next to another.
'river' becomes 'r'.
'bank' becomes 'row' (I've seen this in other clues**).
'spa'+'r'+'row'='SPARROW'
'in' is the link.
(Other definitions for sparrow that I've seen before include "House bird" , "Passerine bird" , "Who killed Cock Robin" , "Small brownish bird" , "Small songbird" .)