Unusually early bird (5)
I believe the answer is:
layer
'bird' is the definition.
The answer and definition can be both animals as well as being singular nouns.
Perhaps there's a link between them I don't understand?
'unusually early' is the wordplay.
'unusually' indicates anagramming the letters.
'early' anagrammed gives 'LAYER'.
Can you help me to learn more?
(Other definitions for layer that I've seen before include "Single thickness, tier" , "Source of eggs" , "Productive chicken" , "Bed - hen" , "See 22" .)