Track a bird (4)

I believe the answer is:

rail

I believe this clue is a double definition.

'track' is the first definition.
('rail' can be a synonym of 'track')

'a bird' is the second definition.
(rail is a kind of bird)

(Other definitions for rail that I've seen before include "Complain intemperately" , "Waterside bird; part of track" , "Complain about - marsh bird" , "Bird with long legs" , "Complain vehemently" .)

I've seen this clue in The Guardian and The Telegraph.

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