This project investigated two endangered and little-studied honeycreepers, the Akohekohe (Palmeria dolei) and Maui Parrotbill (Pseudonestor xanthophrys). The field study extended from 1994-1997. Research objectives were: (1) determine for Akohekohe whether fluctuating food availability leads to emigration to lower elevation and subsequent mortality from mosquito-borne disease; (2) determine rates of nest success for Akohekohe and Maui Parrotbill, including evidence of nest predation by rats; (3) determine changes in native bird populations at Hanawi for the period 1980-1997, during which feral pigs were excluded from the habitat and the vegetation had begun to recover; (4) characterize behavior and life histories of Akohekohe and Maui Parrotbills. It was learned that while flower availability varied seasonally, Akohekohe, unlike related nectar-feeders, generally remained resident on year-round territories and when flowers were scarce did not move to lower elevations, where they would be exposed to non-native, mosquito-borne diseases. The birds' use of flowers in the shrub layer demonstrated the need to exclude pigs from the ecosystem to prevent loss of these important plant species. By monitoring nests, it was discovered that both bird species experienced relatively high rates of nest success, downplaying the urgency to control non-native rats as a means of increasing recruitment. (The birds seem to avoid rats by building their nests high in the leafy canopy.) It was not possible to document changes in bird populations over 25 years, owing to limited data from 1980. However, variability in population estimates among months and years was studied to examine the precision of one-time counts. These results are being applied to the Maui Forest Bird Recovery Project (initiated by HDLNR in FY-97), to a new program to breed the species in captivity for future releases (ZSSD), and to the completely revised Hawaii Forest Birds Recovery Plan, due out in 2001.
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