Avian symbol of revolution in a 1901 poem by Maxim Gorky (6,6)
I believe the answer is:
stormy petrel
(Other definitions for stormy petrel that I've seen before include "Mother Carey's chicken" , "Person who delights in controversy" , "portent of trouble" , "Popular name for sea bird believed to presage bad weather" , "one likely to cause trouble" .)