Mallards recorded per party hr on the Honolulu Christmas Count, O'ahu, 1944-2014

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

with Koloa, the increase in numbers from 1986 to 2009 reflects spreading of a

naturalized population following propagation in the 1950s-1960s, and the decline since 2009 reflects control efforts in support of Hawaiian Duck populations.

 

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/