Tick off "Herons: Birds" (8)

I believe the answer is:

moorhens

'birds' is the definition.
(moorhen is a kind of bird)

'tick off herons' is the wordplay.
'tick' becomes 'mo' (both can mean a very short amount of time).
'off' indicates anagramming the letters.
'herons' with letters rearranged gives 'orhens'.
'mo'+'orhens'='MOORHENS'

I've seen this clue in The Telegraph.

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