Problem Definition-Research

This report contributes to the GEF PAS project "Prevention, eradication and control of invasive alien species in the Pacific islands". It is funded by the Global Environment Facility (GEF), implemented by the United Nations Environment Programme (UNEP) and executed by Secretariat of the Pacific Regional Environment Programme (SPREP) in partnership with the Department of Environment Protection & Conservation, Vanuatu.

Late is an isolated and uninhabited island located about 55 km WSW of the island of Vava'u, in the Kingdom of Tonga. Late supports a tropical broad-leaf forest ecosystem, one of the most threatened ecosystem types in the world and one of the best remaining tracts of diverse native forest in Tonga. Owing to its relatively unmodified forest communities, Late is also a global stronghold for two IUCN listed species of bird, one native mammal, and six species of reptile.

Vatthe the largest Conservation Area, and the most extensive lowland alluvial forest left in Vanuatu, is under threat from an invasive vine, big leaf (Merremia peltata), which is causing the death of large numbers of canopy trees.

Rodent eradications undertaken on tropical islands are more likely to fail than eradications undertaken at higher latitudes. We report on 12 independent rodent eradication projects undertaken on tropical islands that utilized the results of an in situ bait availability study prior to eradication to inform, a priori, the bait application rate selected for the eradication. These projects also monitored bait availability during the eradication.

Invasive mammal eradications are a proven, effective method of restoring damaged ecosystems and preserving biodiversity. On most tropical oceanic islands indigenous land crabs compete with targeted alien species for bait and interfere with traps and detection devices. Current eradication practices are inherited from successful termperate or subantarctic campaigns, yet we do not possess trued and tried methods for managing land crab interference.

The Aleipata islands are considered to be of great regional conservation significance because they are uninhabited (with the exception of Namua), relatively pristine as forest ecosystems, hosting many species threatened throughout the greater Samoa, and still not invaded by most invasive alien species (IAS) present within Upolu main island. Due to this reason they were included in the list of the 7 key biodiversity areas of Samoa (Conservation International et al. 2010).

Lack of biological knowledge of invasive species is recognised as a major factor contributing to eradication failure. Management needs to be informed by a site-specific understanding of the invasion system. Here, we describe targeted research designed to inform the potential eradication of the invasive yellow crazy ant Anoplolepis gracilipes on Nu'utele island, Samoa. First, we assessed the ant's impacts on invertebrate biodiversity by comparing invertebrate communities between infested and uninfested sites. Second, we investigated whether an association existed between A.

Many ant species that have been accidentally spread throughout the world have significant economic, environmental and social impacts in areas that they now infest. One of the most notable invasive ants is the Yellow crazy ant, A. gracilipes, and this species is present in Samoa, including on the Aleipata islands. The Aleipata islands are considered to be of great regional conservation significance because they are uninhabited, relatively pristine, contain many species threatened throughout greater Samoa, and lack many exotic species present within greater Samoa. The presence of A.

The Samoan islands of Nuutele and Nuulua from part of the Aleipata Marine Protected Area, in recognition of their contribution to biological diversity in Samoa. In a 1986 review of 226 islands in the South Pacific region, these islands together rated 30th in importance for biological diversity. The islands provide essential habitat for a reange of sea birds, bats and land birds such as the rare friendly ground dove, sea turtles, shell fish and other marine life.

Rat eradication has become a common conservation intervention in island ecosystems and its effectiveness in protecting native vertebrates is increasingly well documented. Yet, the impacts of rat eradication on plant communities remain poorly understood. Here we compare native and non-native tree and palm seedling abundance before and after eradication of invasive rats (Rattus Rattus) from Palmyra Atoll, Line Islands, Central Pacific Ocean. Overall, seedling recruitment increased for five of the six native trees species examined.