shrew rat
shrew rat, any of 24 species of carnivorous ground-dwelling rodents found only on the tropical islands of Sulawesi (Celebes), the Philippines, and New Guinea. Eighteen species live exclusively at high elevations in cool, wet mossy forests; the other six inhabit lowland and foothill rainforests.
Natural history
These shrewlike mammals have small eyes, long whiskers, wide front feet, and narrow hindfeet with hairless soles. Other characteristics vary depending on the species: the body may be slender or chunky, the ears small or large; the tail may be shorter or longer than the body. The head and muzzle of several species are long and narrow, but among others the head is broad and the muzzle short. Nocturnal shrew rats have gray fur, but diurnal species are reddish brown to almost black. The Philippine striped rats (genus Chrotomys) and the blazed Luzon shrew rat (Celaenomys silaceus) have a stripe running down the back. Fur is generally short, dense, and soft. Its texture is either velvety or woolly, although the prickly coat of the Sulawesi spiny rat (Echiothrix leucura) is a striking exception. The Sulawesi spiny rat is the largest shrew rat, measuring 20 to 23 cm (7.9 to 9.1 inches), not including its slightly longer tail; it weighs 220 to 310 grams (about 8 to 11 ounces). Shrew rats of New Guinea are all very small—the groove-toothed shrew mouse (Microhydromys richardsoni) weighs only 9 to 12 grams and has a body 8 to 9 cm long and an equally long tail.
Shrew rats poke their noses through wet leaf litter and moss to locate their food; those species with long front claws dig deeper into the ground cover and moist underlying soil. On Sulawesi and in the Philippines, large shrew rats share habitat with small white-toothed shrews; the shrew rats eat mostly earthworms, whereas the shrews consume insects. In New Guinea there are no shrews, but shrew rats are their ecological counterparts, primarily eating insects and other invertebrates. In the mountain forests of Sulawesi, some shrew rats are their own counterparts within the same habitat. Greater Sulawesian shrew rats (genus Tateomys) forage for earthworms at night, and the lesser Sulawesian shrew rat (Melasmothrix naso) exploits the same resource during the day.
Classification
Shrew rats belong to the subfamily of Old World rats and mice (Murinae) within the family Muridae of the order Rodentia.
- Genus Chrotomys (Philippine striped rats)
- 4 species.
- Genus Crunomys (Philippine and Sulawesian shrew rats)
- 4 species.
- Genus Tateomys (greater Sulawesian shrew rats)
- 2 species.
- Genus Echiothrix (Sulawesi spiny rats)
- 2 species.
- Genus Rhynchomys (shrewlike rats)
- 2 species.
- Genus Archboldomys (Mt. Isarog shrew mice)
- 2 species.
- Genus Microhydromys (Lesser shrew mice)
- 2 species.
- Genus Pseudohydromys (New Guinean shrew mice)
- 2 species.
- Genus Celaenomys (blazed Luzon shrew rat)
- 1 species.
- Genus Mayermys (One-toothed shrew mouse)
- 1 species.
- Genus Melasmothrix (lesser Sulawesian shrew rat)
- 1 species.
- Genus Neohydromys (Mottled-tailed shrew mouse)
- 1 species.