Loxioides Bailleui)
THE AUK A QUARTERLY JOURNAL OF ORNITHOLOGY VOL. 101 OCTOBER 1984 NO. 4 ANNUAL VARIATION IN THE DISTRIBUTION, ABUNDANCE, AND HABITAT RESPONSE OF THE PALILA (LOXIOIDES BAILLEUI) J. MICHAEL SCOTT,• STEPHENMOUNTAINSPRING, 1 CHARLESVAN RIPER,III, 2 CAMERONB. KEPLER,3 JAMESD. JACOBI,1 TIMOTHY A. BURR,4 AND JON G. GIFFINs •U.S.Fish and WildlifeService, Patuxent Wildlife Research Center, Mauna LoaField Station, Hawaii National Park, Hawaii 96718 USA; 2CooperativeNational Park ResourcesStudy Unit, Departmentof Zoologyand Ecology, Universityof California,Davis, California 95616 USA; 3U.S.Fish and WildlifeService, Patuxent Wildlife Research Center, 248 KaweoPlace, Kula, Hawaii 96790 USA; 4HawaiiDepartment of Landand Natural Resources, Division of Forestryand Wildlife, Honolulu, Hawaii 96813 USA; and SHawaiiDepartment of Landand Natural Resources,Division of Forestryand Wildlife, Kamuela, Hawaii 96743 USA ABSTRACT.--Westudied the distribution, population size, and habitat responseof the Palila (Loxioidesbailleui) during the 1980-1984 nonbreeding seasonsto infer factorsthat limit the population and to develop management strategies.Distribution was fairly constant from year to year. Palila were confined to the subalpinewoodland on Mauna Kea on the island of Hawaii, occurredbetween 2,000 and 2,850 m elevation, and reachedhighest densitieson the southwestslopes. The populationshowed large annual fluctuations,from 6,400 birds in 1981 to 2,000 in 1984. The width of woodland was the most important variable in determin- ing habitat response.Palila were more common in areaswith greater crown cover, taller trees,and a higher proportion of native plants in the understory.Annual variation in Palila density within a habitat reflectedvariation in levels of their staplefood, mamanepods. The main limiting factorsof the population appearedto be the availability of good habitat and levels of their staple food.
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