Faunal remains from archaeological sites on Buka, Nissan, and Tikopia Islands. Southwest Pacific include a number of taxa not previously recorded from those islands. These are Rattus praetor for both Nissan and Tikopia, and Thylogale brunii. Unicomys poneeleti. and Uromys salebrosus for Buka. R. praetor and T. brunii were probably introduced into the region by humans during the mid Holocene. Following the initial expansion in the ranges of these taxa, some island populations became extinct.