Down here fast changes are required (8)

I believe the answer is:

feathers

I'm a little stuck... Click here to teach me more about this clue!

'down' is the definition.
(down can mean bird feathers)

'here fast changes are required' is the wordplay.
'here fast' anagrams to 'FEATHERS'.
Though, I'm unsure how this is indicated.

Can you help me to learn more?

(Other definitions for feathers that I've seen before include "Possibly down" , "Plumages" , "Covering for birds" , "Coverings of birds' bodies" , "''Hope is the thing with ...'' (Emily Dickinson)" .)

I've seen this clue in The Globe and Mail and The Guardian.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.