James C Russell4, Justine D Shaw2,7, Michael Driessen5, Dr Melissa Houghton1,2,3, Mark I Stevens6, Penelope Pascoe7,8, Hugh Possingham2, Aleks Terauds3

0Centre for Biodiversity and Conservation Science, University of Queensland, St Lucia , Australia, 1Department of Natural Resources and Environment Tasmania, New Town , Australia, 3Australian Antarctic Division, Kingston, Australia, 4School of Biological Sciences, University of Auckland, Auckland , Aotearoa / New Zealand, 5School of Geography, Planning, and Spatial Sciences, University of Tasmania, Hobart, Australia, 6Securing Antarctica’s Environmental Future, Earth and Biological Sciences, South Australian Museum, , Australia, 7Securing Antarctica’s Environmental Future, School of Biology and Environmental Science, Queensland University of Technology, Brisbane, Australia, 8Institute for Marine and Antarctic Studies, University of Tasmania, Battery Point, Australia

Biography:

Biography to come.

Abstract:

Invasive mammals have devastating impacts on island biodiversity. In consequence, eradication programs on islands have increased in number, scale and success, and our understanding of native species responses has grown. Yet conservation benefits are rarely quantified for small and cryptic species such as invertebrates. Invertebrates are abundant and respond quickly to changing conditions, making them ideal indicators of ecosystem responses.

House mice (Mus musculus) have invaded islands globally and are a major predator of invertebrates. They were eradicated from sub-Antarctic Antipodes Island and Macquarie Island for conservation purposes, in 2016 and 2011 respectively. On Antipodes mice were the sole invasive mammal, whereas on Macquarie Island they co-occurred with invasive black rats (Rattus rattus) and European rabbits (Oryctolagus cuniculus). Using macro-invertebrate surveys pre- and post- mice eradication on both islands, we assessed changes in richness, diversity, and abundance. Two years after mice were eradicated from Antipodes Island, the richness and abundance of invertebrates preyed upon by mice increased. In contrast, responses were more varied on Macquarie Island four years post-eradication.

We show mice eradications benefit invertebrates on islands and suggest that invertebrate responses are less predictable in ecosystems responding to a multi-species eradication. On Macquarie Island, invasive rabbits and rats had transformed invertebrate habitats, causing long-lasting impacts beyond eradication. Thus, restoration of invertebrate communities may take longer when mouse eradications involve the concurrent removal of other invasive species. Allowing the ecosystem to recover without additional management may not benefit all invertebrate groups.

Keywords

Invasive species, rabbits, sub-Antarctic, invertebrate monitoring, restoration, rodents