Descend to collect some feathers (3,4)
I believe the answer is:
get down
'descend' is the definition.
(I know that get down is a more specific form of the action descend)
'collect some feathers' is the wordplay.
'collect some' becomes 'get' (I can't explain this - if you can you should give a lot more credence to this answer).
'feathers' becomes 'down' (down can mean bird feathers).
'get'+'down'='GET DOWN'
'to' acts as a link.
Can you help me to learn more?
(Other definitions for get down that I've seen before include "you could - from duck" , "Dismount, alight" , "See feathers, > alight" , "Swallow" .)