Mus musculus and Rattus rattus are ubiquitous consumers in
the high-elevation shrubland of Haleakala National Park. Food habits of these
two rodent species were determined from stomach samples obtained by snap-trapping
along transects located at four different elevations during November
1984 and February, May, and August 1985. Mus musculus fed primarily on
fruits, grass seeds, and arthropods. Rattus rattus ate various fruits, dicot leaves,
and arthropods. Arthropods, many of which are endemic, were taken frequently
by Mus musculus throughout the year at the highest elevation where plant
food resources were scarce. Araneida, Lepidoptera (primarily larvae), Coleoptera,
and Homoptera were the main arthropod taxa taken. These rodents,
particularly Mus musculus, exert strong predation pressure on populations
of arthropod species, including locally endemic species on upper Haleakala
Volcano
