Marsupial Rats and Mice
Marsupial rats and mice are a diverse group of about 40 species of small, native carnivores of Australia, Tasmania, and New Guinea, in the family Dasyuridae. The young of marsupial rats and mice, as with those of all marsupials, are born while still in a tiny, embryonic stage of development. The almost helpless babies migrate to the belly of their mother, where they fix on a nipple and suckle until they are ready to lead an independent life. Unusual among the marsupials, the females of some species of marsupial rats and mice do not have a belly pouch (or marsupium) that encloses their nipples and protects their young. Other species do have a permanent pouch, or they have one that develops only during the breeding season.
Marsupial rats and mice are small mammals with a uniformly dark, brownish coat, often with a whitish belly, and they have a superficial resemblance to placental rats and mice. Most species are nocturnal predators that feed on insects and other small prey. The larger species, such as marsupial rats, feed on smaller marsupials, birds, and reptiles, and introduced rodents. In a sense, marsupial mice fill the ecological roles played by the smallest placental predators on other continents, for example, shrews, while the marsupial rats are ecologically similar to larger small predators, such as weasels.
The brush-tailed marsupial mice or brush-tailed tuans (Phascogale spp.) are two species that occur in extreme southern Australia. The broad-footed marsupial mice (Antechinus spp.) are 10 species that occur in Australia, Tasmania, and New Guinea. The fat-skulled marsupial mice (Planigale spp.) are three species that live in Australia and New Guinea. The crested-tailed marsupial mouse (Dasycercus cristicauda) occurs in dry habitats of central Australia. The narrow-footed marsupial mice or pouched mice ( Sminthopsis spp.) are about ten species that occur in various types of habitats in Australia, Tasmania, and New Guinea. The long-legged jumping marsupials or jerboa marsupial mice (Antechinomys spp.) are two rare species of sandy deserts and savannas of Australia.
Many species of marsupial rats and mice have declined greatly in abundance due to habitat loss and the deadly effects of introduced placental mammalian predators, such as cats and foxes. Numerous species are now endangered, and special conservation measures must be taken if they are to survive.