Bird identified by some beautiful markings (6)
I believe the answer is:
fulmar
'bird' is the definition.
(fulmar is a kind of bird)
'some beautiful markings' is the wordplay.
'some' indicates a hidden word (some of the parts of the word are used).
'FULMAR' can be found hidden inside 'beautiful markings'.
'identified by' is the link.
(Other definitions for fulmar that I've seen before include "Get an strange armful of this seabird" , "Heavy short-tailed polar bird" , "Heavy short-tailed oceanic bird" , "Bird of petrel family" , "Gull-like sea bird" .)