Enderby Island at 700 ha still remains the largest island from which the introduced House Mouse Mus musculus has definitely been removed - back in 1993. Enderby is part of New Zealand's Auckland Island group and supports a population of ACAP-listed Southern Royal Albatrosses Diomedea epomophora.
However, since then it seems increasingly likely that aerial bait drops have now succeeded in eradicating House Mice on larger islands in New Zealand. Coal Island, Preservation Inlet, Fiordland National Park (c. 1200 ha, treated in 2008) and Rangitoto/Motutapu (two islands connected by a causeway with a combined area of 3800 ha in the Hauraki Gulf near Auckland and treated in 2009) so far appear mouse-free. These efforts are balanced by failures to eradicate mice at a number of islands, including c. 2000-ha Île Australie in the French Îles Kerguelen. A renewed attempt to clear Australia's Macquarie Island (12 785 ha) of mice (as well as of rabbits and rats) will be made next year, following this year's unsuccessful effort (click here).
Gough Island in the South Atlantic where mice are ravaging the Critically Endangered Tristan Albatross D. dabbenena may be the next large mouse-ridden island at 6500 ha destined for a poison-bait drop. Two New Zealand alien eradication experts, Nick Torr, a private consultant and Chris Golding of the Department of Conservation (DOC), arrived on Gough this week to gather information on (and impressions of) the island towards producing the necessary operational plan. The plan will set out in detail the procedures that need to be followed to achieve eradication (click here to access the Macquarie Island Operational Plan as an example) and to allow a budget to be drawn up.
The plan will be produced on behalf of the United Kingdom's Royal Society for the Protection of Birds (RSPB) with funding from the UK Goverment's Darwin Initiative and Overseas Territories Environment Programme and with the support of the Conservation Department of Tristan da Cunha. The experts' visit to Gough forms part of a large research and management group present on the island at the time of the annual relief of the South African weather station.
Angel, A. & Cooper, J. 2006. A review of the impacts of introduced rodents on the islands of Tristan da Cunha and Gough. RSPB Research Report No. 17. 58 pp. http://www.rspb.org.uk/ourwork/conservation/projects/tristandacunha/publications.asp.
Angel, A, Wanless, R.M. & Cooper, J. 2008. Review of impacts of the introduced House Mouse on islands in the Southern Ocean: are mice equivalent to rats? Biological Invasions 11: 1743-1754.
Golding, C. 2010. Mouse Mus musculus eradication by aerial bait application on Adele, Tonga and Fisherman Islands, Abel Tasman National Park, New Zealand. Conservation Evidence: 7: 62-68. http://www.conservationevidence.com/.
Parkes, J. 2008. A feasibility study for the eradication of House Mice from Gough Island. RSPB Research Report No. 34. 51 pp. ttp://www.rspb.org.uk/ourwork/conservation/projects/tristandacunha/publications.asp.
Torr, N. 2002. Eradication of rabbits and mice from subantarctic Enderby and Rose Islands. In: Veitch, C.R. & Clout, M.N. (Eds). Gland & Cambridge: IUCN SSC Invasive Species Specialist Group. pp. 319-328.
Wanless, R.M., Angel, A., Cuthbert, R.J., Hilton, G.M. & Ryan, P.G. 2007. Can predation by invasive mice drive seabird extinctions? Biology Letters 3: 241-244.
Wanless, R.M., Cooper, J., Slabber, M. & Ryan, P.G. in press. Risk assessment of terrestrially foraging birds on Marion and Gough Islands to primary and secondary poisoning by rodenticides. Wildlife Research.
Wanless, R.M., Fisher, P., Cooper, J., Parkes, J. & Ryan, P.G. 2008. Bait acceptance by House Mice: an island field trial. Wildlife Research 35: 806-811.
Wanless, R.M., Ryan, P.G., Altwegg, R., Angel, A., Cooper, J. Cuthbert, R.[J.] & Hilton, G.M. 2009. From both sides: dire demographic consequences of carnivorous mice and longlining for the Critically Endangered Tristan Albatrosses on Gough Island. Biological Conservation 142: 1710-1718.
With thanks to Chris Golding, Richard Cuthbert and Nick Torr for information.
John Cooper, ACAP Information Officer, on Gough Island, 11 September 2010