Bird sitting next to black dog (6)
I believe the answer is:
beagle
'dog' is the definition.
(beagle is a kind of dog)
'bird sitting next to black' is the wordplay.
I cannot quite understand how this works, but
'bird' could be 'eagle' (eagle is a type of bird) and 'eagle' is present in the answer.
'black' could be 'b' (abbreviation as in pencil classifications) and 'b' is present in the answer.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for beagle that I've seen before include "5 [MANS BEST FRIEND]" , "Small hunting dog" , "Hunting dog followed on foot" , "Type of hound" , "Hound dog" .)