Flyer found in grate, next to something black (8)
I believe the answer is:
nightjar
'flyer' is the definition.
(nightjar is a type of bird, something which flies)
'grate next to something black' is the wordplay.
'grate' becomes 'jar' (both can mean to irritate or annoy).
'next to' means one lot of letters go next to another.
'something black' becomes 'night' (the night sky is black).
'jar' put after 'night' is 'NIGHTJAR'.
'found in' acts as a link.
(Other definitions for nightjar that I've seen before include "Nocturnal bird related to the swift" , "Nocturnal insect-eating bird" , "Noct. bird (of harsh cry)" , "Nocturnal bird with harsh cry" , "Nocturnal bird of swift family" .)