This bird is the bird that got at the ducks (8)
I believe the answer is:
cockatoo
'this bird' is the definition.
(cockatoo is a kind of bird)
'the bird that got at the ducks' is the wordplay.
'the bird' becomes 'cock' (cock is a kind of bird).
'that got' is a charade indicator (letters next to each other).
'the ducks' becomes 'OO' (OO resembles two zeroes or 'ducks' in cricket).
'cock'+'at'+'oo'='COCKATOO'
'is' acts as a link.
(Other definitions for cockatoo that I've seen before include "Australian parrot" , "Illegal Aussie look-out man" , "White parrot" , "Crested bird" , "Bird, a type of parrot" .)