Threatened albatrosses on Marion Island are being scalped by mice

Ben Dilley and colleagues (Percy FitzPatrick Institute of African Ornithology, DST/NRF Centre of Excellence, University of Cape Town, Rondebosch, South Africa) report in the journal Antarctic Science on attacks on albatross chicks by introduced House Mice Mus musculus on Marion Island.

The paper’s abstract follows

“House mice (Mus musculus L.) were introduced to sub-Antarctic Marion Island more than two centuries ago, and have been the only introduced mammal on the island since 1991 when feral cats were eradicated.  The first mouse-injured wandering albatross (Diomedea exulans L.) chick was found in 2003 and since then attacks have continued at a low level affecting <1% of the population.  In 2009, the first ‘scalpings’ were detected; sooty albatross (Phoebetria fusca Hilsenberg) fledglings were found with raw wounds on the nape.  In 2015, mice attacked large chicks of all three albatross species that fledge in autumn: grey-headed (Thalassarche chrysostoma Forster) (at least 102 wounded chicks; 4.6% of fledglings), sooty (n=45, 4.3%) and light-mantled albatross (P. palpebrata Forster) (n=1, 4%).  Filming at night confirmed that mice were responsible for wounds.  Attacks started independently in small pockets all around the island’s 70 km coastline, separated by distances hundreds of times greater than mouse home ranges.  The widespread nature of mouse attacks in 2015 on large, well-feathered chicks is alarming and highlights not only Marion Island as a priority island for mouse eradication but also that mice alone may significantly affect threatened seabird species.”

 Scalped Grey-headed Abatross chicks, photograph by Ben Dilley

Wandering Albatross chick being attacked by mice, photographs by Stefan Schoombie

Click here for a popular account on scalping by mice at Marion Island.

With thanks to Susan Mvungi, Niven Library, University of Cape Town for information.

Reference:

Dilley, B.J., Schoombie, S., Schoombie, J. & Ryan, P.G. 2015.  ‘Scalping’ of albatross fledglings by introduced mice spreads rapidly at Marion Island.  Antarctic Science doi.org/10.1017/S0954102015000486.

John Cooper, ACAP Information Officer, 13 November 2015