Seabird I rouse after Manx cat, perhaps (9)
I believe the answer is:
kittiwake
'seabird' is the definition.
(kittiwake is a kind of seabird)
'i rouse after manx cat perhaps' is the wordplay.
'rouse' becomes 'wake' (I've seen this before).
'after' says to put letters next to each other.
'manx' means to remove the last letter (Manx cats have no tail).
'cat perhaps' becomes 'kitty'.
'kitty' with its last letter taken off is 'kitt'.
'i'+'wake'='iwake'
'iwake' after 'kitt' is 'KITTIWAKE'.
(Other definitions for kittiwake that I've seen before include "Oceanic gull" , "Arctic gull with yellow bill and black legs" , "Small pearl-grey gull" , "Bird" , "A seagull" .)