Black-crowned Night-Herons recorded per party hr on the
Honolulu Christmas Count, O'ahu, 1948-2007 (see Count Page).
The increase may reflect, in part, increasingly comfortable cohabitation with humans,
having become common sights foraging around city boat docks and parks. 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/