Above picture: Mouse attack! This breeding Wandering Albatross found dead on Marion Island in April 2023 showed clear signs of wounds caused by House Mice; photograph by Michelle Risi
Maëlle Connan (Marine Apex Predator Research Unit, Nelson Mandela University, Gqeberha, South Africa) and colleagues have published early view and open access in the journal Biological Invasions on observations of introduced House Mice Mus musculus attacking and killing adult Critically Endangered Tristan Albatrosses Diomedea dabbenena on Gough Island and adult Vulnerable Wandering Albatrosses D. exulans on Marion Island. Previous mortality records for both species were of chicks only. The death of breeding adults confirms the need to eradicate the mice. Unfortunately, the attempt by the Gough Island Restoration Programme to eradicate Gough’s mice in 2021 failed. Eradication of the mice on Marion Island (which will incorporate any necessary lessons learned from the Gough failure) is set to take place in winter 2026, according to the Mouse-Free Marion Project.
The corpse of a female adult Tristan Albatross found after being attacked by mice on Gough Island in April 2021; photograph by Roelf Daling
The paper’s abstract follows:
“Invasive rodents threaten native species in numerous ecosystems, especially oceanic islands. The House Mouse Mus musculus is the only introduced mammal species on sub-Antarctic Gough and Marion Islands. Ample evidence exists of mice preying upon seabird chicks on these two islands, but there have been only a few reports of attacks on adult seabirds, none of which has been fatal. We report the first deaths of adult great albatrosses due to mouse attacks. On Gough Island, three Tristan Albatrosses Diomedea dabbenena (Critically Endangered) brooding small chicks were observed with wounds typical of mouse attacks in March-April 2021; two likely abandoned their chick, causing breeding failure, and the third was found dead eight days after discovery with large blowfly larvae in the wound. On Marion Island, two wounded and eight dead adult Wandering Albatrosses D. exulans (Vulnerable) were found in April 2023. Inspection of the wounded individuals, as well as the injuries on the fresh carcasses strongly suggest that mouse predation was the cause of death. Gough Island is home to virtually all Tristan Albatrosses, and Marion Island is the single most important breeding site for Wandering Albatrosses, home to about a quarter of all breeding birds. The death of breeding adults of these long-lived species emphasizes the urgent need to eradicate introduced mice from these islands.”
Another view of the dead Wandering Albatross on Marion Island with typical wounds caused by mice on its wings; photograph by Chris Jones
With thanks to Maëlle Connan, Roelf Daling, Chris Jones and Michelle Risi.
Reference:
Connan, M., Jones, C.W., Risi, M.M., Smyth, L.K., Oppel, S., Perold, V., Stevens, K.L., Daling, R. & Ryan, P.G. 2023. First evidence of mouse predation killing adult great albatrosses. Biological Invasions doi.org/10.1007/s10530-023-03177-2.
John Cooper, News Correspondent, Mouse-Free Marion Project, 14 November 2023
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A Grey-headed Albatross colony on Marion Island; photograph and poster design by Michelle Risi
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.
