Attention put on avian habitat is serious (3)
I believe the answer is:
ear
'attention' is the definition.
(having someone's ear is having their attention)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for ear that I've seen before include "Musical ability" , "Musical appreciation" , "Organ involved with balance" , "Auditory organ" , "organ with drum" .)