Mouse predation on Laysan albatross

Invasive rodents on islands have adverse impacts on native birds in island ecosystems, and rats are the most common culprits. Recently, house mice (Mus musculus) in the South Atlantic were found preying on three species of albatross chicks. Here, we show that house mice can also prey on nesting adult Laysan albatross (Phoebastrea immutabilis) on Midway Atoll National Wildlife Refuge (USA). In contrast to mouse attacks on albatross in the South Atlantic where mice targeted the rump and crown of chicks, on Midway, mice targeted nesting adults mainly on the back. For both regions, the outcome was similar with reduced nesting success. In the case of Midway, reduced nesting success was due to nest abandonment or mortality of one or both parents due to secondary bacterial infections. Mortality of adult albatross has the potential to have a more potent demographic impact due to their much higher natural survivorship once they reach adulthood. We discuss possible reasons why mice preyed on live albatross. Pursuant to these findings, efforts are currently under way to eradicate mice on Midway Atoll.