Stretch your neck to see a bird (5)
I believe the answer is:
crane
'stretch' is the definition.
(I know that crane is a kind of stretch)
'your neck to see a bird' is the wordplay.
I cannot really understand how this works, but
'see' could be 'c' (the word for the letter, according to Chambers) and 'c' is found within the answer.
'a' could be 'an' and 'an' is found in the answer.
The remaining letters 're' 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 crane that I've seen before include "Bird; hoister" , "Device for picking up" , "Lifting structure" , "Tall wading bird can lift heavy loads" , "Bird; dockside machine" .)