Little Bittern
Ixobrychus minutus
This is a very difficult species to prove breeding and there are sporadic records, indicative of territory holding at the least, since about 1800. East Anglia and Kent are the usual, but not only, sites. Only instance of proved breeding was 1984 in Yorkshire (and present following year).
Ogilvie, M.A. & RBBP 1999 British Birds: 92, 176-182 & 472-476.
From The State of the Nations Birds
Copyright © 2000 by Chris Mead