Pacific rat (Rattus exulans), yellow crazy ant (Anoplolepis gracilipes)
The islands of Nu’utele (108ha) and Nu’ulua (25ha) are part of the Aleipata Island Group. They lie 1.3km from the coast of Upolu Island, Samoa. Pacific rats (Rattus exulans) have been present on Nu’utele since 1991 and Nu’ulua since 2003. The Pacific rat is a predator of native insects, lizards and birds, as well as of seeds fruits and flowers. As a result, this rat is recognised as a major conservation pest. Both Nu’utele and Nu’ulua have long been recognised as key sites for conservation in Samoa. They present important opportunities as sanctuaries for native species whose survival is threatened by rats on the main islands of Samoa (Upolu and Savai’i). It is proposed to eradicate rats from the Aleipata Islands in order to restore their flora and fauna. Removing the rats will also present opportunities to use the island as a refuge for native species threatened by rats and other invasive species on the main islands of Samoa.
An operational plan to eradicate Pacific rats is being prepared by David Butler Associates Ltd in consultation with the Ministry of Natural Resources, Environment and Marine (Samoa) and PII staff. The operation will involve applying grain-based baits containing the toxin brodifacoum using a helicopter and an under-slung bucket. Both Nu’utele and Nu’ulua feature steep terrain, Nu’utele having vertical cliffs up to 180 metres high. This would make manual baiting for rats difficult and dangerous, thus the proposal for an aerial bait drop. This aerial application approach has been used successfully elsewhere, including on large steep islands.
In addition to eradicating rats it is proposed to experimentally reduce yellow crazy ant (Anoplolepis gracilipes) densities on Nu’ulua Island. Large numbers of the ants are active throughout the forest and may have already led to significant changes in the island’s ecology. Opportunities to combine rat and ant management are being considered, but further investigation is required to determine the feasibility of such an approach.
Tooth-billed Pigeon (Manumea) (Dr U. Beichle)
Aleipata Islands provide habitat for a number of locally and regionally endemic land birds including; the tooth-billed pigeon (Didunculus strigirostris) (endemic, Endangered), the friendly ground dove (Gallicolumba stairi) (regional endemic, Vulnerable) and the Samoan broadbill (Myiagra albiventris) (endemic, Vulnerable). They also hold the largest seabird colonies in Samoa - breeding seabirds include; red footed and brown boobies (Sula sula and Sula leucogaster), black and white terns (Sterna sumatrana and Gygis alba) and the great frigatebird (Fregata minor) . Other inhabitants on the islands include the Vulnerable coconut crab, (Birgus latro) and an endemic bat (Pteropus samoensis).
- NZAID, New Zealand's International Aid and Development Agency
- Regional Natural Heritage Programme (RNHP) through the Critical Ecosystem Partnership Fund (CEPF)
Souad Boudjelas - email@example.com