Getting Rid of Rats on Pacific Atolls

Forest and Bird, Issue 310, 1 November 2003, Page 11

Getting Rid of Rats on Pacific Atolls

DEE PIGNEGUY

meets two New Zealand environmentalists aboard their catamaran on Aitutaki Lagoon.

returning from an expedition to Suwarrow Atoll National Park where — with the help of volunteers — they had completed the first phase of a rat eradication project funded by the New Zealand Ministry of Foreign Affairs "Pacific Initiatives for the Environment program. They had been trapping rats to establish the population and species of the rodents on the 25 motu (islets) of Suwarrow. (See Forest & Bird, February 2001.) ‘We found only Pacific rats (kiore), and they were only on motu west of the pass, which makes about half the land area of Suwarrow already rat free’ This is very good news they say, pointing out ‘the less poison used the less the danger to the local environment. They also want to promote small-scale ecotourism on Suwarrow and other remote islands of the Cooks, and have submitted an environmental impact report to the local Environment Service for permission to do so. They talked excitedly of New Zealander Elspeth Wingham who works for UNESCO administering the World Heritage Convention in the Pacific. She has put together a plan involving the governments of the Cook Islands, French Polynesia, Kiribati, and the USA to consider forming a Line Islands World Heritage Site. This could involve some 20 remote uninhabited islands belonging to these nations being classified under the UNESCO convention. At present all of the candidate islands have rats and many have cats, so there should be plenty of restoration work for volunteers willing to pay their keep during these efforts. ‘Overwhelmingly, New Zealand leads the world in rat eradication and island restoration, says Ed Saul, and this expertise may be put to the test after the recent Manu Tuamotu Expedition, which was financed jointly by the New Zealand Ministry of Foreign Affairs and the U.S. Fish and Wildlife Service. The Bounty Bay and her crew of scientists spent five weeks visiting 10 uninhabited islands in March this year. The only other recent visitors had been islanders collecting birds and turtles to eat and harvesting coconuts. The islands had been virtually unknown scientifically for many decades. ‘We struck gold with Morane, the southernmost of the | Ed Saul and zoologist Dr Graham Wragg were

archipelago, said Dr Wragg. "There were no rats or cats and the motu had populations of two species of land birds, the endangered Tuamotu sandpiper and the critically endangered Tuamotu ground dove. The Tuamotu ground dove is known only from one other population in the world (on Tenararo in the Actéon Group). Dr Philippe Raust of the French Polynesian Ornithological Society (SOP-Manu, an affiliate of BirdLife International) and Dr Ray Pierce of Whangarei were also involved with the expedition. As well as counting bird populations, the expedition was looking for suitable islands for rat eradication and ecological

restoration. This would be followed by the re-introduction of plants and animals that had been eradicated by rats and cats and the monoculture of the coconut plantations. Unwilling to disturb the resident endangered bird species, the overnight shore expedition was unable to find a suitable campsite on Morane. Finally settling on a ‘little bit of unused dirt’, they were surprised to discover a couple of leeches crawling on their legs. The question, ‘Has anyone ever seen a leech on an eastern Pacific atoll?’ was answered by the thought that perhaps elsewhere the rats have exterminated even the leeches. Another mystery for future expeditions to solve... — DEE PIGNEGUY