Bird, duck takes advantage of first of ponds in school (5,7)
I believe the answer is:
house sparrow
'bird' is the definition.
(house sparrow is a kind of bird)
'duck takes advantage of first of ponds in school' is the wordplay.
'duck' becomes 'o' (resembles zero - 'duck' in cricket).
'takes advantage of' becomes 'uses' (I've seen this in another clue).
'first of' suggests taking the first letters.
'in' means one lot of letters goes inside another.
'school' becomes 'harrow' (famous UK public school).
The first letter of 'ponds' is 'p'.
'o'+'uses'+'p'='ousesp'
'ousesp' inserted inside 'harrow' is 'HOUSE SPARROW'.
(Other definitions for house sparrow that I've seen before include "one chirpy?" , "Winger" , "Flier" .)