Bird to listen to — the last to fly up! (4)

I believe the answer is:

rhea

'bird' is the definition.
(rhea is a kind of bird)

I don't understand how the rest of the clue works.

(Other definitions for rhea that I've seen before include "Small 'ostrich'" , "Ostrich-like bird - satellite of Saturn" , "Flightless bird - Greek fertility goddess" , "Grounded bird" , "China grass" .)

I've seen this clue in The Times.

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