Proceedings of the Vertebrate Pest Conference

The United Kingdom’s Overseas Territories support the vast majority of the globally threatened species for which the UK is responsible. Henderson Island (43 km²), located in the South Pacific and part of the Pitcairn Islands group, is a near-pristine example of a raised coralline atoll and is internationally recognized as a UNESCO World Heritage Site. Pacific (Polynesian) rats, introduced by Polynesian settlers about 700 years ago, have been implicated in the long-term decline towards extinction of the Henderson petrel, the loss of huge numbers of breeding seabirds from the island, and the extinction of endemic species. The eradication of Pacific rats is the only viable management option open to prevent the eventual extinction of the Henderson petrel and is a vital action in maintaining the Outstanding Universal Value of this World Heritage Site. The Royal Society for the Protection of Birds (RSPB), in partnership with the Government of the Pitcairn Islands, undertook a multi-year program of planning, fundraising, and partnership-building work which culminated in a GBP£1.5m (USD$2.4m) aerial bait dispersal operation in 2011. The work was carried out in August 2011 as part of an international “chain” of eradication operations (Palmyra Atoll, USA, and Enderbury and Birnie, Kiribati) carried out in succession. Seven months after completion of the operation, in March 2012, the first report of a rat sighting was received. This report was verified by a rapid response mission to the island in May 2012, followed by a further expedition to Henderson in November to assess the status of rat and bird populations. Concurrently, the RSPB began an evaluation process, commissioning 3 independent reviews of the entire operation in an effort to identify potential reasons for failure and maximize lessons learnt for the global eradication community. We conclude that a rigorous yet flexible planning process that engages both international expertise and local communities is essential. We make recommendations for consideration in the planning of future operations on Henderson and similar islands worldwide.