A fruitbat, Decitabine Pteropus tonganus, shows significant declines in frequency, although it survived on the island. Similar impacts are recorded for marine fish and shellfish ( Butler, 2001), including measurable resource depression in several species. These impacts on the local biota were accompanied by the introduction of the Pacific rat, pig, dog, and chicken. Pig husbandry became important during the island’s middle phase, but as with the Tikopia case, pigs were later eliminated from the

subsistence system. This is presumed to reflect trophic competition with humans for carbohydrates as human population densities increased ( Kirch, 2001). Whereas Tonga, Tikopia, and Mangaia are all relatively small islands, the Hawaiian Islands are a subtropical archipelago rich in a variety of microenvironments GSK1120212 purchase and resources that incorporate eight major islands and many smaller islets with 16,698 km2 of land area. Unsurprisingly,

the extent of Polynesian impact on the Hawaiian Islands was not as total as on the smaller islands; significant parts of the Hawaiian landscape remained relatively unaffected by human land use and resource exploitation at the time of initial European contact. Nonetheless, the lowland zones (i.e., land below ca. 600–900 m) of the main islands exhibited extensive anthropogenic modification, in some areas with almost complete human conversion and manipulation of the land surface in intensive food production systems. Extensive multidisciplinary research on Polynesian ecodynamics in Hawai’i has resulted in a richly documented record that we cannot do full justice only to here (Olson and James, 1984, Athens, 1997, Burney et al., 2001, Athens et al., 2002, Vitousek et al., 2004, Kirch, 2007 and Kirch et al., 2012). Pollen records from O‘ahu and Kaua’i islands document major transformations in the lowland vegetation communities

of those islands soon after Polynesian arrival ca. A.D. 1000, including the elimination of coastal Pritchardia palm forests on O‘ahu. These dramatic vegetation changes were probably due to a combination of clearing for gardens and other land use activities, combined with the effects of introduced rats on vulnerable native seeds and seedlings. Such forest clearance also led to localized erosion and deposition of sediments in the lowlands, in-filling valley bottoms and embayments. The lowland forests were habitats for a number of flightless birds, including four endemic genera of anatids (ducks or geese) and one ibis, all of which became extinct within a relatively short period following Polynesian arrival. The Hawaiian land snails, a classic case of adaptive radiation and high degree of endemism (in such families as Achatinellidae, Amastridae, and Endodontidae), also saw significant extinction or local extirpation episodes related to forest clearance, and possibly to direct predation by Polynesian introduced ants ( Christensen and Kirch, 1986).