Duck small victim for hunting bird (6)
I believe the answer is:
osprey
'hunting bird' is the definition.
(ospreys hunt)
'duck small victim' is the wordplay.
'duck' becomes 'o' (resembles zero - 'duck' in cricket).
'small' becomes 's' (abbreviation - e.g. clothes size).
'victim' becomes 'prey' (prey is a kind of victim).
'o'+'s'+'prey'='OSPREY'
'for' acts as a link.
(Other definitions for osprey that I've seen before include "Large fish-eating bird of prey" , "Fish-hawk" , "One flying" , "Large bird preying on fish in inland waters" , "Fish-eater" .)