Adult Red-footed Boobies counted primarily at Kilauea
Point NWR, Kaua'i, breeding colony, as recorded on the Kapa'a
Christmas Count 1972-2014 (see Count
Page), indicating a significant
increase during 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/