Hawaiian Ducks (Koloa) recorded per party hr on the Honolulu Christmas

Count, 1944-2014 (see Count Page), showing a slight increase in observations during the 1970s-1990s, due to re-propogation programs, followed by a decline through the 2000s and a large increase after 2008. Most observations of these ducks after the 1990s were identified as hybrids with Mallard.


Species account.


Graphs of Christmas Count data developed as part of The Birds of the Hawaiian

Islands: Occurrence, History, Distribution, and Status by Robert L. Pyle and Peter Pyle http://hbs.bishopmuseum.org/birds/rlp-monograph/