Down here fast changes are required (8)

I believe the answer is:

feathers

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'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 Guardian and The Globe and Mail.

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