Eradication of Pacific rats (Rattus exulans) from Fanal Island, New Zealand. C. R. Veitch Department of Conservation, Private Bag 68-908, Newton, Auckland, New Zealand. Present address: 48 Manse Road. Papakura, New Zealand. E-mail:
[email protected] Abstract Fanal Island (73 ha) is the largest island in the Mokohinau Group, Hauraki Gulf, New Zealand. Pacific rats, or kiore, (Rattus exulans) reached these islands between about 1100 and 1800 A.D. Pacific rats were removed from all islands in this group, except Fanal Island, in 1990. An aerial application of Talon 7-20 (containing brodifacoum at 20 ppm) at a nominal rate of 10 kg/ha was made on Fanal Island on 4 August 1997 with the intention of eradicating the rats. Despite heavy rainfall immediately after the poisoning operation, and the fact that baits were not of optimum palatability, the rats were eradicated. Keywords Bitrex; brodifacoum; aerial baiting. INTRODUCTION cations they were presumed to be detrimental to natural Fanal Island (Motukino), 73 ha, is the largest and most processes (Holdaway 1989; Atkinson and Moller 1990). southerly island in the Mokohinau Group which is at the Pacific rats were removed from all islands in this group, northern extremity of the Hauraki Gulf, about mid way except Fanal Island, by the Department of Conservation between Great Barrier Island and the mainland (Fig. 1). in 1990 (McFadden and Greene 1994). Fanal Island is part of Mokohinau Islands Nature Reserve, Under the Regulations Act 1936 and the Grey-faced Pet- which is administered by the Department of Conservation rel (Northern Muttonbird) Notice 1979, Ngati Wai of Aotea under the Reserves Act 1977.