Crow discovered food container for smaller avian species (5)
I believe the answer is:
robin
'smaller avian species' is the definition.
(bird species)
'crow discovered food container' is the wordplay.
'discovered' says to take the centre (dis-covered - outer letters removed).
'food container' becomes 'bin' (eg a bread bin).
The centre of 'crow' is 'ro'.
'ro'+'bin'='ROBIN'
'for' acts as a link.
(Other definitions for robin that I've seen before include "See 7" , ". . . . . Hood was a medieval outlaw" , "Batman's companion" , "See 12" , "Red and brown songbird" .)