Eradication

The Island of Suwarrow and its surrounding waters was declared a National Park in 1978 under the Conservation Act 1975. The legal opinion sought in 2001 clarifies that Suwarrow is Crown Land. Today, Suwarrow is under the jurisdiction of the National Environment Service (NES) since 2003, for the primary purpose of conserving, preserving, protecting and managing the natural resources of Suwarrow.

To enhance their conservation value, several hundred islands worldwide have been cleared of invasive alien rats, Rattus spp. One of the largest projects yet undertaken was on 43 km2 Henderson Island in the Pitcairn group, South Pacific, in August 2011. Following massive immediate mortality, a single R. exulans was observed in March 2012 and, subsequently, rat numbers have recovered. The survivors show no sign of resistance to the toxicant used, brodifacoum.

This study describes the biodiversity values of Malden Island, Kiribati, and assesses the potential benefits, feasibility and costs of removing key invasive species. Malden is relatively pest-free, but two significant invasive species are present - feral house cats and house mice. We believe that the most cost-effective and beneficial conservation action in the short term for Kiribati is to undertake a cat eradication programme.

The Ministry of Environment, Lands and Agricultural Development (MELAD) has received funds through

A programme to eradicate two species of myna from Kiribati was carried out between November 2014 and November 2015 by staff of the Environment & Conservation Division, Ministry of Environment, Lands and Agricultural Development with funds through the regional GEF-PAS Invasives project coordinated by UNEP and SPREP, assisted by international consultant Dave Butler.

This report is based on official trip made to Onotoa early this year 2014. IAS project under ECD together with ALD from MELAD was made to fulfill the obligation of ECD as an implementing agency. In 2012, there is a survey trip made to confirm the distribution and number of myna birds on Onotoa in order to set up appropriate actions to cease the disturbances and destruction caused by this bird.

Invasive rodents have an overwhelmingly detrimental impact to native flora and fauna on islands. Rodent eradications from islands have led to valuable biodiversity conservation outcomes. Tropical islands present an additional suite of challenges for rat eradications due to unique characteristics associated with these environments. To date tropical island rat eradications have failed at a higher rate than those undertaken outside the tropics. Critical knowledge gaps exist in our understanding of what drives this outcome.

Rat eradications on tropical islands have been less successful than operations in temperate climates. This is likely due to poor understanding of the factors unique to tropical regions that rat populations respond to, such as high numbers of land crabs, aseasonal climates and habitats not found at higher latitudes. On Aldabra Atoll, southern Seychelles, black rats were monitored for one year in three habitats over three climatic seasons to investigate changes in density and breeding to inform planning for a possible rat eradication.

Invasive rats are found on most island groups of the world, and usually more than one species has invaded. On tropical islands populations of different invasive rat species can co-exist on very small islands, but the population dynamics of such co-existing rat species, their impact on each other, and the mechanisms of coexistence are not well known. This lack of knowledge is a barrier to improving the success rate of tropical island rat eradications.