Bird disturbed by hikers (6)
I believe the answer is:
shrike
'bird' is the definition.
(shrike is a kind of bird)
'disturbed by hikers' is the wordplay.
'disturbed by' indicates an anagram (inserted letters disturb or break up the word).
'hikers' with letters rearranged gives 'SHRIKE'.
(Other definitions for shrike that I've seen before include "Butcher bird" , "Songbird with a heavy hooked bill" , "Butcherbird" , "Predatory songbird" , "Shriek like kind of bird" .)