List contains duck and crowing bird (7)
I believe the answer is:
rooster
'crowing bird' is the definition.
(I've seen this before)
'list contains duck' is the wordplay.
'list' becomes 'roster' (a roster is a list or register).
'contains' is an insertion indicator.
'duck' becomes 'o' (resembles zero - 'duck' in cricket).
'roster' placed around 'o' is 'ROOSTER'.
'and' is the link.
(Other definitions for rooster that I've seen before include "Domestic cock" , "Cockerel (mainly US)" , "male with comb" , "Farmyard bird" , "One may crow" .)