Metachirus nudicaudatus, brown four eyed opossums, range from Nicaragua to Paraguay and N. Argentina (Redford and Eisenburg, 1992).

Biogeographic Regions: neotropical (Native )

In general, M. nudicaudatus is grayish-brown in color. The back and sides are darker brown. The head has a dark band stretching from the tip of the snout over the eyes and across the base of the ear, making the face look almost black. In some individuals, this band extends past the ears. The eyes are large, rounded, and completely dark. A creamy white spot over each eye gives the animals their "four-eyed" name. The fur is short, thick, and silky. The venter (belly or abdomen) is usually white or cream. The tail is furred partially near the base. The rest of the tail, the scaly part, is multicolored--part black and part white. The length of the tail is usually around 330 mm, being longer than the body which is about 265 mm (Nowak, 1997; Redford and Eisenburg, 1992). The females are 71% lighter than the males (Hansen et al., 1999).

Range mass: 800 (high) g.

Range length: .570 to .630 m.

Other Physical Features: endothermic ; bilateral symmetry

Average basal metabolic rate: 1.144 W.

• Terrestrial

Brown four eyed opossums are both arboreal and terrestrial, but more often are found on the ground. They inhabit lowlands, heavy forests, or open brush country. They build round nests in tree branches or at times under rocks and logs (Hunsaker, 1977). The nests are made of leaves and twigs (Nowak, 1997).

Range elevation: 700 (high) m.

Habitat Regions: tropical

Terrestrial Biomes: forest ; scrub forest

This species is mainly frugivorous. However, their diet can also include insects, bird's eggs, small vertebrates such as reptiles, and also small invertebrates (Hunsaker, 1977). In a study which examined the feces of individuals, some brown four eyed opossums were found to consume more ants, termites, cockroaches and beetles than any other food in their diet (Freitas et al., 1997).

Animal Foods: amphibians; eggs; insects

Plant Foods: fruit

Primary Diet: herbivore (Frugivore )

As an insectivore, M. nudicaudatus clearly helps to keep the numbers of insects in its habitat under control (Freitas et al., 1997).

Ecosystem Impact: disperses seeds

The maximum lifespan of M. nadicaudatus is three to four years (Nowak, 1997)

Range lifespan

Status: wild: 3-4 (high) years.

Average lifespan

Status: captivity: 4.0 years.

Mating System: polygynandrous (promiscuous)

Brown four eyed opossums are seasonally polyestrous, meaning that they are capable of breeding many times through out the year. In Central America, though, they are reported to breed in November. The female of this species does not have a pouch like most marsupials. Instead lateral folds of skin exist on the lower abdomen, on which the mammae are located (females with 5, 7, and 9 have all been recorded). Therefore, the young does not crawl into the pouch after birth like other marsupials. A 51-mm young was reported to be capable of standing on its own. It rode on its mother's hips or back and was fully independent 2 months later (Nowak, 1997).

Breeding season: seasonally polyestorus, November (Central America)

Range number of offspring: 1 to 9.

Key Reproductive Features: gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (Internal ); viviparous

Average number of offspring: 5.

Parental Investment: altricial ; female parental care

US Federal List: no special status

CITES: no special status

IUCN Red List of Threatened Species: least concern

This species has been accused of destroying fruit crops in certain areas (Nowak, 1997).

Negative Impacts: crop pest

Brown four eyed opossums consume pests such as ants, termites, and cockroaches (Frietas et al., 1997).

Positive Impacts: controls pest population