Above Picture: A Grey-headed Albatross on Australia’s Macquarie Island, now free of introduced vertebrates, including House Mice, following successful eradication efforts. Photograph by Melanie Wells

Dena Spatz (Senior Conservation Scientist, Pacific Rim Conservation, Honolulu, Hawaii, USA) and colleagues have published open access in the journal Scientific Reports on a synthesis of 1550 eradication attempts of introduced vertebrates on 998 islands over a 100 years, with an 88% success rate and a steadily increasing size of treated islands.

The senior author writes to MFM News: “This study shows that invasive species eradication from islands is a common and highly successful tool, applied across the world’s islands. These results strengthen our confidence in pursuing crucial restoration projects, particularly on biodiversity hotspots such as South Africa’s Marion Island, where the Mouse-Free Marion Project removing the invasive mice will protect threatened seabirds and provide global-scale biodiversity and ecosystem benefits.”

She adds “Our study found that success rates from invasive species eradications are high and have remained stable over time. This is a testament to the hard work of people and partnerships seeking to prevent species extinctions and restore island ecosystems” (click here).

The authors’ findings and endorsement give encouragement to the Mouse-Free Marion Project in its planning to eradicate the island’s invasive House Mice. It has also given a welcome morale boost to the project team!

The problem: a mouse-scalped Grey Headed Albatross chick on Marion Island. The Mouse-Free Marion Project is working towards eradicating the albatross-killing mice. Photograph by Ben Dilley

The paper’s abstract follows:

“Islands are global hotspots for biodiversity and extinction, representing ~ 5% of Earth’s land area alongside 40% of globally threatened vertebrates and 61% of global extinctions since the 1500s. Invasive species are the primary driver of native biodiversity loss on islands, though eradication of invasive species from islands has been effective at halting or reversing these trends. A global compendium of this conservation tool is essential for scaling best-practices and enabling innovations to maximize biodiversity outcomes. Here, we synthesize over 100 years of invasive vertebrate eradications from islands, comprising 1550 eradication attempts on 998 islands, with an 88% success rate. We show a significant growth in eradication activity since the 1980s, primarily driven by rodent eradications. The annual number of eradications on islands peaked in the mid-2000s, but the annual area treated continues to rise dramatically. This trend reflects increases in removal efficacy and project complexity, generating increased conservation gains. Our synthesis demonstrates the collective contribution of national interventions towards global biodiversity outcomes. Further investment in invasive vertebrate eradications from islands will expand biodiversity conservation while strengthening biodiversity resilience to climate change and creating co-benefits for human societies.”

Read a popular account of the publication here.

With thanks to Dena Spatz.

Reference:

Spatz, D.R., Holmes, N.D., Will, D.J., Hein, S., Carter, Z.T., Fewster, R.M., Keitt, B., Genovesi, P., Samaniego, A., Croll, D.A., Tershy, B.R. & Russell, J.C. 2022. The global contribution of invasive vertebrate eradication as a key island restoration tool. Scientific Reports 12, 13391. doi.org/10.1038/s41598-022-14982-5.

John Cooper, News Correspondent, Mouse-Free Marion Project, 23 August 2022

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The Mouse-Free Marion Project is a registered non-profit company (No. 2020/922433/08) in South Africa, established to eradicate the invasive albatross-killing mice on Marion Island in the Southern Ocean. The project was initiated by BirdLife South Africa and the South African Department of Forestry, Fisheries and the Environment. Upon successful completion, the project will restore the critical breeding habitat of over two million seabirds, many globally threatened, and improve the island’s resilience to a warming climate. For more information or to support the project please visit mousefreemarion.org.