Oma'os recorded per party hr
on the Volcano Christmas Count, Hawai'i,
1972-2007 (see Count
Page), showing a significant
decline through the period. 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/