Erckel Francolins recorded per
party hr on the Waipi'o Christmas Count, O'ahu, 1977-2014 (see Count
Page), perhaps showing an
increase through the 1990s followed by a decline through the 2000s. 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/