Annual variation in the distribution, abundance, and habitat response of the palila ( Loxioides bailleui).

Abstract

Distribution was fairly constant from year to year. Palila were confined to the subalpine woodland on Mauna Kea, Hawaii, occurred between 2000-2850m elevation, and reached highest densities on the SW slopes. The population showed large annual fluctuations, from 6400 birds in 1981-2000 in 1984. The width of woodland was the most important variable in determining habitat response. Palila were more common in areas with greater crown cover, taller trees, and a higher proportion of native plants in the understory. Annual variation in density within a habitat reflected variation in levels of staple food, mamane pods. The main limiting factors of the population appeared to be the availability of good habitat and levels of their staple food. The most effective management strategies would be the removal of feral ungulates and certain noxious plants from palila habitat and the extension of the woodland zone to areas now intensively grazed.-from Authors