By Aarti Mandavia
Geographic Range
Monodelphis brevicaudata is predominantly found in the South American countries of Venezuela, the Guyanas, Columbia, parts of Brazil, and Bolivia. (NatureServe, 2003; Ventura, Perez-Hernandez, and Lopez-Fuster, 1998)
Biogeographic Regions:
neotropical 
(native ).
Habitat
Red-legged short-tailed opossums live mainly in forests and in shrubby areas with a great deal of vegetation. Nests have been reported in the hollows of trees. (Eisenberg and Redford, 1999; Linares, 1998)
These animals are found in the following types of habitat:
tropical ; terrestrial .
Terrestrial Biomes:
forest ; scrub forest .
Physical Description
(2.36 to 3.34 oz)
(6.3 in)
Red-legged short-tailed opossums have a body length of approximately 16 cm, a tail length of roughly 9 cm, and weigh between 67 and 95 g. Males are reported to be slightly larger than females.
One distinctive feature of M. brevicaudata is that members of the species usually have grey or black fur on their backs, reddish fur on their sides continuing onto the legs, and black feet and tail. Their tails are very short and furred. Their fur is usually short and dense.
The skull is characterized by the presence of the jugal and zygomatic arch. The dental formula of this opossum species is 5/4, 1/1, 3/3, 4/4= 50. (Eisenberg and Redford, 1999; Engstrom, Lim, and Reid, 1999; Wible, 2003)
Some key physical features:
endothermic ; bilateral symmetry .
Sexual dimorphism: male larger.
Reproduction
The breeding interval of these animals is not known.
The breeding season of this species has not been reported.
There is relatively little known about the mating patterns of M brevicaudata in particular. It may be similar to that of other didelphids, which are polygynous. Competition between males may be extreme, and male opposums are often intollerant of one another. Because of the sexual dimorphism in size seen in this species, it is likely that they are similar to other members of their family. (Cockrum, 1962; Linares, 1998; Nowak, 1997)
Mating systems:
polygynous .
There is not a great deal that is known about the reproduction of the M. brevicaudata. Although data for this species are scant, within one member of the genus the period of estrus was found to last 3 to 12 days, and the estrous cycle showed a bimodal distribution, being about 2 weeks long in one of captive females and about 1 month long in another group. The species usually reproduces during the dry season and they produce between 6 and 8 young. Reproduction of this species may be similar to that of other opossums which have an average gestation period of 12.5 days. (Cockrum, 1962; Linares, 1998)
Regardless of the actual length of gestation, we can assume that because these animals are marsupials, the gestation is short, and the young are born fairly undeveloped. Because the pouch of females is not well developed in this genus, it is likley that the young must cling to the nipple until they are large enough to ride on the back of their mother. (Nowak, 1997)
Young are dependent upon their mother until about 50 days after birth. Sexual maturity in the genus Monodelphis is reached between 4 and 5 months of age, and breeding may occur as late as 39 months of age in males and 28 months in females. (Nowak, 1997)
It is not known how frequently these animals reproduce, and it is not possible to generalize from other members of the genus. Some species in Monodelphis are apparently semelparous, with few individuals living past their first reproduction. Others may produce up to four litters per year. (Nowak, 1997)
Key reproductive features:
gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous .
There is no information about the specific parental investment of red-legged, short-tailed opossums. It is likely that the female, who provides nourishment for the young gives most, if not all of the parental care. The pouch of these animals is reported to be poorly developed, and so the young must cling to a nipple until they are large enough to ride on the the mother's back. The role of the male in parental care of M. bevicaudata is not known. (Nowak, 1997)
Parental investment:
no parental involvement; altricial ; pre-fertilization (protecting: female); pre-hatching/birth (protecting: female); pre-weaning/fledging (provisioning: female, protecting: female).
Lifespan/Longevity
The lifespan of M. brevicaudata is unknown.
Behavior
Behavior of M. brevicaudata is still being explored. However, it is know that these mammals are solitary and usually asocial creatures. It is also known that they are diurnal, territorial and terrestrial. They are motile on the ground and occasionally in trees. (Eisenberg and Redford, 1999; Linares, 1998)
Home Range
The home range size for these animals has not been reported.
Communication and Perception
Details of the communciation patterns of M. brevicaudata are not available. The species is reported to have tactile and chemical perception channels. As diurnal mammals, we can assume that they also use vision to some extent, and it is likely that they communicate with one another using body postures and other visual signals. Vocalizations have not been reported, but probably occur.
Food Habits
Red-legged short-tailed opossums generally eat insects such as cockroaches and crickets and small animals such as spiders, but also eat fruit and seeds on occasion. (Linares, 1998)
Primary Diet:
carnivore (insectivore ).
Animal Foods:
insects; terrestrial non-insect arthropods.
Plant Foods:
fruit.
Predation
Details on the predation of M. brevicaudata are unknown, but common didelphid predators include owls, coyotes, foxes, and bobcats.
Ecosystem Roles
Through its foraging behavior, M. brevicaudata probably has a role in the regulation of insects and small animal populations in its habitat. To the extent that these animals serve as prey for predators, they may also have some affect on predator populations.
Economic Importance for Humans: Negative
There are no known negative consequences of this species on humans.
Economic Importance for Humans: Positive
There are no known positive effects of this species on humans.
Conservation Status
IUCN Red List: [link]:
Lower Risk - Least Concern.
US Federal List: [link]:
No special status.
CITES: [link]:
No special status.
There is no special conservation status for M. brevicaudata. Howver,there are reportes that most members of the genus are declining due to habitat destruction. (Nowak, 1997)
For More Information
Find Monodelphis brevicaudata information at
Contributors
Aarti Mandavia (author), University of Michigan. Phil Myers (editor, instructor), Museum of Zoology, University of Michigan.
Nancy Shefferly (editor), Animal Diversity Web Staff.
