Prepare to fire at ducks or another bird (8)
I believe the answer is:
cockatoo
'another bird' is the definition.
'cockatoo' can be an answer for 'bird' (cockatoo is a kind of bird). I am unsure of the 'another' bit.
'prepare to fire at ducks' is the wordplay.
'prepare to fire' becomes 'cock' (as in cocking a gun).
'ducks' becomes 'oo' (two O's - duck means zero in cricket).
'cock'+'at'+'oo'='COCKATOO'
'or' acts as a link.
Can you help me to learn more?
(Other definitions for cockatoo that I've seen before include "Australasian parrot" , "Parrot native to Australia and Indonesia" , "Illegal Aussie look-out man" , "Australian parrot" , "Bird, a type of parrot" .)