Storm petrels are affected by House Mice on an albatross island in the South Atlantic

Mark Bolton (Royal Society for the Protection of Birds, Sandy, UK) and colleagues have published in the journal Polar Biology on the effects of House Mice Mus musculus on storm petrels on Steeple Jason, an island in the Falkland Islands (Islas Malvinas)* that supports a very large population of ACAP-listed Black-browed Albatrosses Thalassarche melanophris as well as Southern Giant Petrels Macronectes giganteus.

The paper’s abstract follows:

"Whilst there is good evidence for negative impacts of introduced rat species on island ecosystems, the effects of house mice (Mus musculus) are generally less well documented. In some situations, introduced house mice can exert severe impacts, particularly where this is the only introduced mammal. Here, we examine the distribution, relative abundance and breeding success of small burrowing seabirds on Steeple Jason Island, Falklands, in relation to habitat types and the distribution of house mice which is the sole introduced mammal species, and we make comparisons with seabird distribution and densities on the neighbouring island of Grand Jason where mice are absent. Grey-backed storm-petrel (Garrodia nereis) and Wilson’s storm-petrel (Oceanites oceanicus), which due to their extremely small size are likely to be the most vulnerable to mouse predation, were considerably more abundant on mouse-free Grand Jason than on Steeple Jason. Grey-backed storm-petrel, which are typically associated with tussac grass, avoided this habitat on Steeple Jason where it is associated with high levels of house mouse activity (assessed from the proportion of wax baits gnawed overnight), whereas on mouse-free Grand Jason, there was no such avoidance. Wilson’s storm-petrel nesting on Steeple Jason suffered high rates of egg and chick loss. Whilst we found evidence for detrimental impacts of house mice on the two small storm-petrel species, there was no relationship between relative mouse activity levels and the distribution or abundance.”

Black-browed Albatrosses on Steeple Jason, photograph by Ian Strange

Click here for a related paper on Steeple Jason's mice.

Reference:

Bolton, M., Stanbury, A., Baylis, A.A.M. & Cuthbert, R.[J.] 2014.  Impact of introduced house mice (Mus musculus) on burrowing seabirds on Steeple Jason and Grand Jason Islands, Falklands, South Atlantic. Polar Biology DOI 10.1007/s00300-014-1554-2.

John Cooper, ACAP Information Officer, 23 August 2014

*A dispute exists between the Governments of Argentina and the United Kingdom of Great Britain and Northern Ireland concerning sovereignty over the Falkland Islands (Islas Malvinas), South Georgia and the South Sandwich Islands (Islas Georgias del Sur y Islas Sandwich del Sur) and the surrounding maritime areas.