Northern Cardinals recorded per party hr on the Volcano
Christmas Count, Hawai'i, 1972-2014 (see Count
Page), showing an increase from
the 1970s through 1990 followed by fluctuating populations into the 2010s. 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/