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This review of the invasive land vertebrates present on islands of the South Pacific Regional Environment Programme (SPREP) region is part of a larger review of the invasive plants and animals that have affected these islands adversely.

Kiritimati Atoll's avifauna has regional and international significance. The Atoll provides nesting roosting, feeding and migration sites for over 40 bird species.

Williamson and Sabath (1982) have demonstrated a significant relationship between modern population size and environment by examining atoll area and rainfall in the Marshall Islands. The present work seeks to extend that argument into prehistory by examining the relationship of ancient habitation sites and size of aroid pit agricultural systems to atoll land area and rainfall regime along the 1,500-3,500 mm precipitation gradient in the Marshall Islands. Four atolls were selected for study: Ebon at the wettest extent in the extreme south; Ujae and Maloelap near the center of the archipelago; and Utrok at the dry north. The first phase of this long-term archaeological program is reported. During the survey of Ujae Atoll (90 05' N, 165° 40' E), three habitation sites, an aroid pit agricultural zone, one early historic burial, and seven fish traps, weirs, and enclosures were recorded. Along with excavations at two habitation sites (8 m2 total area), 35 traditional artifacts were recovered (shell adzes, ornaments, and manufacturing tools). Seven radiocarbon age determinations document land use beginning as early as the third century A.D. A beachrock sample dated to 2450 ± 70 BP relates to atoll development. Some 4,748 bones of fish, birds, turtles, Pacific rats, lizards, humans, and possible cetaceans, along with nearly 13 kg of shellfish, provide the basis for understanding prehistoric subsistence, human adaptations to the atoll setting, and land use patterns.

Henderson island, a World Heritage Site in the Pitcairn group, south-central Pacific Ocean, has often been thought to have a pristine vegetation. Our archaeological investigations and field observations in 1991-1992, supported by recent observations in 1997, suggest the occurrence of former areas of Polynesian cultivation near to the North and East Beaches, and indicate that about 17 non-native vascular plant taxa have occurred. The majority of these were deliberate Polynesian introductions, some taxa are known only as sub-fossils from Polynesian occupation sites; some of this sub-fossil material may represent imported plant parts such as timber or food wraps, rather than indicating in situ cultivation. These Polynesian introductions show little spread from their probable site of introduction and are mostly restricted to the vicinity of the northern beaches; some have become extinct on Henderson. The Pitcairn islanders have also introduced a small number of vascular plants, and one of these (Passiflora maliformis) is potentially invasive. Other taxa have been accidentally introduced, at least one by a recent scientific expedition in 1991. The intact nature of much of the native vegetation may have restricted the opportunities for more widespread colonization; care is needed to ensure that this situation persists.

As requested by the Pacific Islands Committee, Council of Western State Foresters, we conducted a survey of selected Micronesian islands for invasive plant species. The objectives were three-fold: (1) To identify species on the islands that are presently causing problems: (2) to identify species that, even though they are not presently a major problem, could spread to other islands where they are not present, potentially causing problems: and (3) to look for invasive species known to cause problems in ecosystems similar to the islands visited. This report is based 011 perceptions gained from a three- week trip from July 19 to August 6, 1998, to the islands of Saipan and Tinian (Commonwealth of the Northern Marianas Islands): Peleliu, Babelthaup and Koror (Republic of Palau); Pohnpei and Yap (Federated States of Micronesia) and Guam.

Disposal of solid waste is a world-wide problem. The Small Island Developing States (SIDS) of the Pacific increasingly share in this problem. As the economies of the island States develop and move toward a cash based, consumer goods society, the volumes and complexity of waste products increase. However, unlike the mainly organic waste of the past, much of the modem waste stream may take many years to break down. Some components of the waste may be harmful. Inadequately managed waste disposal has the potential to affect the health of the people, damage the environment of the islands and be a barrier to economic development, Further discussion on the extent of the problem in the region may be found in SPREP (1998): "Solid Waste Issues in Pacific ACP Countries" by Dr Suresh Raj.

This is the final report describing the results from the second and third years of a three-year programme to determine the costs and benefits of aerial 1080 possum control operations to North Island robins (Petroica australis longipes) and moreporks (Ninox novaeseelandiae) in Pureora Forest Park, North Island, New Zealand. During this study robins were individually colour-banded, and moreporks radio-tagged in both treatment and non-treatment study areas. A poison operation using carrot baits in August 1997 covered 8577 ha and incorporated the 300 ha Waimanoa study area. A poison operation using cereal baits in August 1998 covered just the 200 ha Long Ridge study area. After the 1997 operation, very few possums remained alive and rat foot-print tracking indices remained very low during the robin nesting season (September 1997 February 1998). Similarly, possum and rat population indices were much reduced after the 1998 operation, but rats and possums were found in a small portion of the study area, presumably because it did not receive baits. Following both the 1997 and 1998 poison operations, there was no significant difference in the proportion of banded robins that disappeared from the non-treatment and treatment study areas. During the 1997/98 nesting season, the nesting success of robins was significantly better in the treatment area than in the non-treatment area. One year after the poison operation (spring 1998), the robin population in the treatment area had increased by 37% on the number present just prior to the poison operation, compared with 16.3% in the non-treatment area. No radio-tagged moreporks were available in the treatment area during the 1997 poison operation, and all three radio-tagged in each of treatment and non-treatment areas were still alive two months after the poison operation in 1998.