What twitchers do to find romantic couple (9)
I believe the answer is:
lovebirds
'what twitchers' is the definition.
I can't tell whether this definition defines the answer.
'do to find romantic couple' is the wordplay.
I cannot quite understand how this works, but
'couple' could be 'love' (loving is a kind of coupling) and 'love' is found in the answer.
The remaining letters 'birds' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for lovebirds that I've seen before include "Affectionate parrots" , "Small African parrots or romantic couple" , "Small African parrots or romantic couples" .)