Hawaiian land practices prior to European contact probably destroyed most of the forest on Niihau. Grazing animals were introduced to the island beginning in the 1700s.
Cattle, goats, sheep, and pigs have decreased available habitat for Pritchardia aylmer-robinsonii as well as directly damaging trees, seedlings, and/or seeds.
(Wagner,W.L., D.R. Herbst, and S.H. Sohmer. 1990. Manual of the Flowering Plants of Hawaii.)
(Beccari and Rock. 1921.)
(Cuddihy and Stone.1990.)
(U.S. Fish and Wildlife Service,pers.comm.1992. )