MARSUPIALIA Family DIDELPHIDAE
Brown Four-Eyed Opossum
, brown four eyed opossums, range from
to Paraguay and N. Argentina (Redford and
Eisenburg, 1992). Native: Neotropical
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). Mass: 800 g (max). Length:
.570 to .630 male larger.
The maximum lifespan of M. nudicaudatus
is three to four years (Nowak, 1997).
As an insectivore, M. nudicaudatus
clearly helps to keep the numbers of insects in
its habitat under control (Freitas et al.,
1997). Disperses seeds.
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). Foods
eaten: fruit, small vertebrates and
invertebrates, insects, and bird’s eggs.
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 polyestrous, November (Central
Number Produced: 1 to 9 Sexual; internal;
viviparous Polygynandrous (promiscuous), Young
altricial; female parental care.
Brown four eyed opossums are completely
nocturnal, hardly moving from their nests until
dark. In a capture-mark-recapture study over two
years, M. nudicaudatus was found to be
highly mobile and exploratory. It also had a
short residence time. It has been observed that
when M. nudicaudatus is held in the hand
it hardly makes any noise (Nowak, 1997; Gentile
and Cerquiera, 1995). Nocturnal; solitary.
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). Elevation: 700 m (max).
Tropical; forest, scrub forest.
Economic Importance for Humans
Brown four eyed opossums consume pests such as
ants, termites, and cockroaches (Frietas et al.,
1997). Controls pest population.
This species has been accused of destroying
fruit crops in certain areas (Nowak, 1997).
IUCN: No special status
U.S. ESA: No special status
U.S. MBTA: 1
CITES: No special status
Freitas, Simone R., Diego Astua De Moraes,
Ricardo T. Santori and Rui Cerqueira. 1997.
Habitat preference and food use by Metachirus
nudicaudatus and Didelphis aurita in a
restinga forest at Rio de Janeiro. Revista
Brasileira de Biologia 57(1):93-98.
Gentile, Rosana and Rui Cerqueria. 1995.
Movement patterns of five species of small
mammals in a Brazilian restinga. Journal of
Tropical Ecology 11(4):671-677.
Hansen, Richard C., J.-C. Vie, N. Vidal and J.
Kervac. 1999. Body measurements on 40 species of
The Zoological Society of
Hunsaker II, Don. 1977. Biology of Marsupials.
Academic Press, New York. Nowak, Ronald M.
1997. “Walker’s Mammals of the World” (On-line),
(Oct. 8, 2001)
Rodford, Kent H. and Jon F. Eisenburg. 1992.
Mammals of the Neotropics.
This article is reproduced with many thanks and
acknowledgements to the author and the
Michigan Animal Diversity Web
and the Smithsonian Institute.
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Reference written by Leeann Bies, Bio 451:
Mammalogy sec 6 (Myers/Teeter)