Rodent

While eradication projects on large islands require substantial funding and a high level of technical and logistical support, projects on small islands are much simpler and can achieve success with much less funding and outside assistance. The Pacific has thousands of such islands that can contribute to significant biodiversity outcomes. The purpose of this guide is to assist the practitioner in removing invasive rodents from small islands (less than 20 hectares) where access to all parts of the island is possible.

Rattus rattus, or black rats, are rampaging through Tuvalu's atolls and gnawing through the country's chief export crop - coconuts.

Invasive vertebrates are a leading cause of the extinction on islands and rats (Rattus spp.) are one of the most damaging to island ecosystems. Methods to eradicate rates from islands are well established and there have been over 580 successful eradications to date. Increasingly, rat eradications are being implemented on tropical islands, a reflection of the need to protect the threatened biodiversity in the tropics. Yet rat eradications on tropical islands fail more frequently than those in temperate climates.

The use of rodenticides to control or eradicate invasive rats (Rattus spp.) for conservation purposes has rapidly grown in the past decades, especially on islands. The non-target consequences and the fate of toxicant residue from such rodent eradication operations have not been well explored. In a cooperative effort, we monitored the application of a rodenticide, ‘Brodifacoum 25W: Conservation’, during an attempt to eradicate Rattus rattus from Palmyra Atoll.