Least Bittern (Ixobrychus exilis) Science Article 4
Evidence for a partial prenuptial moult in the Little Bittern Ixobrychus minutus is reported for the firsttime, and is based on both live and museum specimens. The prenuptial moult, which is probablyundertaken in the African winter quarters shortly before the spring migration, involves body feathersand often some innermost secondaries. The moult pattern is discussed in the context of the Ardeidaeand compared with those of other Ixobrychus species. Current ageing criteria are also reconsidered.
FRANCESCO PEZZO and ANDREW G. GOSLER, Ringing & Migration (2005) 22, 129-132