PATHOLOGY OF HOUSE MOUSE (MUS MUSCULUS) PREDATION ON LAYSAN ALBATROSS (PHOEBASTRIA IMMUTABILIS) ON MIDWAY ATOLL NATIONAL WILDLIFE REFUGE.

Invasive rodents on islands have adverse effects 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 (Phoebastria immutabilis) on Midway Atoll National Wildlife Refuge (US). 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 because of secondary bacterial infections. Mouse-induced mortality of adult albatross has the potential to have a more potent demographic effect because of their much higher natural survivorship once they reach adulthood.