Mallards recorded per party hr on the Honolulu Christmas Count, O'ahu, 1944-2007

(see Count Page). The observations in the 1940s may have represented confusion

with Koloa, and the increase in numbers since 1986 reflects spreading of a

naturalized population following propagation in the 1950s-1960s.

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/2009/