Henderson Island

Invasive species

On 1 February 2010, a report detailing the state of conservation of Henderson Island was submitted by the State Party. The report provides an overview of the implementation of the invasive rat eradication scheme, the planned ranger appointment, and also briefly describes the status of additional conservation issues of concern, including sustainable use of timber, turtle nesting beaches, ex-situ conservation and translocation, endemic fauna and flora, invasive species, and cetaceans.

a) Rat eradication

The State Party reports that the last remaining conservation obstacles to a programme of rat eradication by poisoned bait, i.e. Henderson crake mortality and bait consumption by land crabs (Gecarcinidae), have been solved. A 2009 eradication field trial funded by the United Kingdom Government found that: i) Henderson crakes could be captured and held in captivity for at least four weeks, therefore avoiding exposure to the poisoned bait; and ii) all rats were able to access and feed on bait pellets despite the high density of land crabs. Moreover, the trial found that endemic snails exposed to bait pellets did not experience significant mortality rates. The State Party further notes that the Operational Plan for the rat eradication programme has been prepared as part of a project managed by the Royal Society for the Protection of Birds (RSPB), and that work is underway to secure the £1.25 million funding necessary for the eradication operations.

The World Heritage Centre and IUCN welcome the progress achieved by the State Party in addressing the conservation obstacles to the rat eradication scheme. The principal long-standing threat to the Outstanding Universal Value of the property is predation by the Polynesian rat on chicks of the endemic Henderson petrel (Pterodroma atrata); in particular: a recent study concluded that rat predation represents a threat of extinction to the Henderson petrel. The World Heritage Centre and IUCN consider it essential that the State Party rapidly secures the funding necessary for the rat eradication operations, indicated at £1.25 million.

b) Ranger Post

The State Party reports that a Ranger Post on Henderson Island is considered feasible and has been discussed in collaboration with the Island Council and the wider community. To date, a job description has been drafted, a basic accommodation plan developed and shipping logistics considered. The State Party further notes that funding for a Ranger posting has been submitted by the Government of Pitcairn Islands to the Overseas Territories Environment Programme (OTEP), and that a decision on funding is expected in February 2010. The World Heritage Centre and IUCN welcome the progress achieved by the State Party and the Pitcairn authorities in establishing a Ranger Post on Henderson Island.

c) Sustainable use of timber, turtle nesting beaches, ex-situ conservation and translocation status of fauna and flora, and status of cetaceans

The State Party reports briefly on the above conservation issues of concern:

i. The State Party considers that there is no risk to the sustainability of miro and tou stocks on Henderson Island. The Pitcairn Islanders have not visited Henderson to harvest miro and tou since 2004 as Magareva Island donated miro wood to Pitcairn in 2007 and additional miro wood has been harvested on Pitcairn Island itself;

ii. With respect to turtle nesting beaches, the State Party reports that the most likely threat to these beaches would be increased visitor numbers and/ or tourism developments. Given that there is no increase in tourism, and no plans for tourism infrastructure, turtle nesting beaches are not considered to be threatened;

iii. With respect to ex-situ conservation, translocation and extinction, the State Party considers that given the absence of increased threats to Henderson Island, no plans for the above have been made, with the exception of testing whether the Henderson crake bird could be successfully kept in captivity during the rat eradication programme;

iv. With respect to endemic flora and fauna and other invasive species, the State Party reports that no endemic species have become extinct in the life of the current Henderson Management Plan, and that there is no evidence of new invasive species on Henderson over the last year. The State Party further notes that the Henderson petrel has been added to the appendices of the Convention on the Conservation of Migratory Species (CMS) with the full support of the Henderson Island Management Committee;

v. With respect to the status of cetaceans, the State Party reports that 6-8 humpback whales were resident off Henderson Island over a six week period in August-September 2009. Furthermore, the State Party notes that a Memorandum of Understanding (MOU) for the Conservation of Cetaceans and their Habitats in the Pacific Island Region has been signed by the Governor of Pitcairn Islands under the auspices of the CMS.

The World Heritage Centre and IUCN note the State Party’s report and commend the State Party’s initiative in placing the Henderson petrel in the appendices of the CMS, and the initiative of the Pitcairn Islands in signing an MOU with CMS concerning the conservation of cetaceans, and consider that the key conservation issues remain the rat eradication programme and appointing a full-time Ranger on Henderson Island.

d) Environmental Strategy for the Pitcairn Islands

The State Party provided a copy of the Pitcairn Islands Environment Management Plan 2008 in annex to its state of conservation report for Henderson Island. IUCN and the World Heritage Centre note that the State Party and the Pitcairn Authorities took care to ensure the compatibility of this management plan with the Henderson Island Management Plan.

e) Status of the management plan

The State Party report outlines the progress against the targets set out in the Henderson Island World Heritage Site Management Plan 2004-2009. Overall the six targets of this Plan have been achieved or adequately addressed, including appointing members of the Henderson Island Management Committee, who have submitted a funding bid to OTEP to update the Henderson Island Management Plan.

In conclusion, the World Heritage Centre and IUCN consider that the State Party should be commended for the considerable progress achieved in planning the rat eradication scheme and in securing a full time Ranger Post for Henderson Island, and strongly advise the State Party to rapidly secure the funding necessary to undertake the rat eradication scheme, as well as adequate funding for a full time Ranger Post on Henderson Island. They note that without the implementation of the rat eradication programme, the threats to the Outstanding Universal Value of the property would become critical.