Here, a bird might stand for a fish (5)
I believe the answer is:
perch
'fish' is the definition.
(I know that perch is a type of fish)
'here a bird might stand' is the wordplay.
I cannot really see how this works, but
'a' could be 'per' (eg 'one a day' means 'one per day') and 'per' is found in the answer.
The remaining letters 'ch' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
'for a' is the link.
Can you help me to learn more?
(Other definitions for perch that I've seen before include "Rod on which bird roosts" , "Bird's seat - fish" , "[SOMETHING FISHY]" , "Bird's resting place or old measure of length" , "What angler may catch" .)