White Terns recorded per party hr on the Honolulu
Christmas Count, O'ahu, 1944- 2014 (see Count
Page), showing the increasing trend, in
winter abundance at least, since this species colonized Honolulu in the 1970s. 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/