Alien ignoring second appearance of a bird (6)
I believe the answer is:
martin
'bird' is the definition.
(martin is a kind of bird)
I don't understand the rest of the clue.
(Other definitions for martin that I've seen before include "Bird of the swallow family" , "Man's name; bird" , "Swallow-like bird" , "Kind of swallow" , "Bird; in tram (anag.)" .)