Sky Larks recorded per party hr on the Waipi'o Christmas Count, O'ahu,
1977-2014 (see Count
Page), showing an increase
through 1990 followed by a decline to near absence through the early 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/