Above Picture: Face of the problem.  A House Mouse on Marion Island, photograph by Stefan Schoombie 

This post continues an occasional series that features the several scientific papers that give information on attacks by House Mice on the birds of Marion Island.  For the first post in the series click here. 

A paper was published on South Africa’s intention to rid its sub-Antarctic Marion Island of House Mice Mus musculus in the 2019 Proceedings of an international Island Invasives Conference held in 2017 in Dundee, Scotland.  Among the paper’s co-authors were representatives of the then South African Department of Environmental Affairs (now DFFE), the FitzPatrick Institute of African Ornithology (FIAO) at the University of Cape Town, the Royal Society for the Protection of Birds (RSPB) and BirdLife South Africa. 

The paper’s abstract follows: 

“House mice (Mus musculus) were introduced to South Africa’s sub-Antarctic Marion Island, the larger of the two Prince Edward Islands, by sealers in the early 19th century.  Over the last two centuries they have greatly reduced the abundance of native invertebrates.  Domestic cats (Felis catus) taken to the island in 1948 to control mice at the South African weather station soon turned feral, killing large numbers of breeding seabirds.  An eradication programme finally removed cats from the island by 1991, in what is still the largest island area cleared of cats at 290 km².  Removal of the cats, coupled with the warmer and drier climate on the island over the last half century, has seen increasing densities of mice accumulating each summer.  As resources run out in late summer, the mice seek alternative food sources.  Marion is home to globally important seabird populations and since the early 2000s mice have resorted to attacking seabird chicks.  Since 2015 c. 5% of summer-breeding albatross fledglings have been killed each year, as well as some winter-breeding petrel and albatross chicks.  As a Special Nature Reserve, the Prince Edward Islands are afforded the highest degree of protection under South African environmental legislation.  A recent feasibility plan suggests that mice can be eradicated using aerial baiting.  The [then] South African Department of Environmental Affairs is planning to mount an eradication attempt in the winter of 2021 [now 2023], following a partnership with the Royal Society for the Protection of Birds to eradicate mice on Gough Island in the winter of 2020.  The eradication programme on Marion Island will be spearheaded by the South African Working for Water programme – Africa’s biggest conservation programme focusing on the control of invasive species –which is already driving eradication projects against nine other invasive species on Marion Island.” 

The published feasibility study on the eradication of House Mice on Marion Island by John Parkes that was funded by BirdLife South Africa formed the platform for the conference paper.  Together with the donation of three Bölkow BO105 helicopters and a generous grant from Dr Frederik Paulsen Jr of the Mamont Foundation, after representation by FitzPatrick Institute Director Professor Peter Ryan, this culminated in a Memorandum of Understanding being signed by the Department of Environment, Forestry and Fisheries (now DFFE) and BirdLife South Africa to implement the Mouse-Free Marion project to eradicate the House Mice on Marion Island. 

Significant progress is being made, and the ambition is to mount the eradication attempt as soon as the requisite funding can be secured.  Every year delayed will mean the loss of tens of thousands of seabirds to predation by mice, and there is now a real intensity to raise the remaining funding. 

Reference: 

Preston, G.R., B.J. Dilley, J. Cooper, J. Beaumont, L.F. Chauke, S. L. Chown, N. Devanunthan, M. Dopolo, L. Fikizolo, J. Heine, S. Henderson, C.A. Jacobs, F. Johnson, J. Kelly, A.B. Makhado, C. Marais, J. Maroga, M. Mayekiso, G. McClelland, J. Mphepya, D. Muir, N. Ngcaba, N. Ngcobo, J.P. Parkes, F. Paulsen, S. Schoombie, K. Springer, C. Stringer, H. Valentine, R.M. Wanless & P.G. Ryan 2019.  South Africa works towards eradicating introduced house mice from sub-Antarctic Marion Island: the largest island yet attempted for mice.  In: Veitch, C.R., Clout, M.N., Martin, A.R., Russell, J.C. & West, C.J. (Eds).  Island Invasives: Scaling up to meet the Challenge.  Gland, Switzerland: IUCN.  pp. 40-46. 

 

John Cooper, Member, Scientific and Technical Advisory Group, Mouse-Free Marion Project, 07 September 2021