The bird flying out is able to (6)
I believe the answer is:
Here is my best explanation:
'the bird' is the definition.
(toucan is a kind of bird)
'flying out is able to' is the subsidiary indication.
'flying' indicates anagramming the letters.
'is able to' becomes 'can' (I've seen this before).
'out' anagrammed gives 'tou'.
(Other definitions for toucan that I've seen before include "A pair could be able for this bird, by the sound of it", "Large bird", "Bird with large colourful beak", "Bird with a large brightly-coloured beak", "exotic bird", "Bird with large, colourful bill", "Coloured tropical bird with a large beak", "Showy bird", "Tropical American bird with immense beak" and "Large-billed tropical bird".)