Spotted bird in the short run (6)
I believe the answer is:
thrush
'spotted bird' is the definition.
'thrush' can be an answer for 'bird' (thrush is a kind of bird). I am not certain of the 'spotted' bit.
'the short run' is the wordplay.
'short' means to remove the last letter.
'run' becomes 'rush' (rush is a kind of run).
'the' with its final letter removed is 'th'.
'th'+'rush'='THRUSH'
'in' acts as a link.
Can you help me to learn more?
(Other definitions for thrush that I've seen before include "Bird - fungal disease" , "sprue" , "Small songbird" , "Songster" , "Songbird with brownish back and speckled breast" .)