Machine packing seed for bird (9)
I believe the answer is:
sandpiper
'bird' is the definition.
(sandpiper is a kind of bird)
'machine packing seed' is the wordplay.
'machine' becomes 'sander' (sander is a kind of machine).
'packing' indicates putting letters inside (some letters are packed inside).
'seed' becomes 'pip' (as in a fruit pip).
'sander' placed around 'pip' is 'SANDPIPER'.
'for' is the link.
(Other definitions for sandpiper that I've seen before include "Stint" , "Shorebird found on sniper pad" , "Shore wader" , "knot" , "Small wading bird with a slender bill" .)