Bird landed finally on slope (5)
I believe the answer is:
drake
'bird' is the definition.
(drake is a kind of bird)
'landed finally on slope' is the wordplay.
'finally' indicates one should take the final letters.
'on' is a charade indicator (letters next to each other).
'slope' becomes 'rake' (rake is a kind of slope**).
The last letter of 'landed' is 'd'.
'd'+'rake'='DRAKE'
(Other definitions for drake that I've seen before include "Raked (anag.)" , "Male billed" , "adventurer from Devon" , "Might he have bowled" , "Elizabethan sailor" .)