Home range and territoriality of two Hawaiian honeycreepers, the 'Akohekohe and Maui Parrotbill

Hawaiian honeycreepers have radiated into a diversity of trophic niches and patterns of space-use. We investigated space-use in two honeycreeper speci es, the 'Akohekohe (Palmeria dolei), an endangered nectarivore, and Maui Pa rrotbill (Pseudonestor xanthophrys), an endangered wood excavator, by mappi ng the home ranges and dispersion of color-banded individuals at a study si te in relatively undisturbed montane cloud forest on Maui Island, Hawai'i. With 20% of outlying points excluded, home-range size averaged much smaller for adult male 'Akohekohe (0.56 ha) than for male Maui Parrotbill (2.26 ha ). In both species, a female's home range mostly overlapped that of her mat e. Adult male Maui Parrotbill defended year-round home ranges from which th ey excluded conspecifics except for their mates and dependent offspring. Al though our data suggest that 'Akohekohe also maintained all-purpose territo ries, the evidence is less convincing because these birds were seen feeding in the home ranges of other individuals. By defending all-purpose territor ies, these two species depart from the more common honeycreeper pattern of sharing large, undefended home ranges.