Great Frigatebirds recorded per party hr on the Honolulu
Christmas Count, O'ahu,
1944-2014 (see Count
Page). The peak in counts during the late
1950s through
1970s reflects increased offshore activity of seabirds
related to an outflow of sewage
from the city during that period (see Pomarine Jaeger account).
Species account
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/