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 ofis 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, et al., 1999; Wible, 2003)
- Sexual Dimorphism
- male larger
- Range mass
- 67 to 95 g
- 2.36 to 3.35 oz
- Average length
- 16 cm
- 6.30 in
- Average basal metabolic rate
- 0.366 W
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 System
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)
- Breeding interval
- The breeding interval of these animals is not known.
- Breeding season
- The breeding season of this species has not been reported.
- Range number of offspring
- 6 to 8
- Average number of offspring
- Average time to independence
- 50 days
- Range age at sexual or reproductive maturity (female)
- 4 to 5 months
- Range age at sexual or reproductive maturity (male)
- 4 to 5 months
There is no information about the specific parental investment of M. bevicaudata is not known. (Nowak, 1997). 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
- Parental Investment
- no parental involvement
The lifespan ofis unknown.
- Average lifespan
- 3.9 years
- Average lifespan
The home range size for these animals has not been reported.
Communication and Perception
Details of the communciation patterns ofare 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.
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)
- Animal Foods
- terrestrial non-insect arthropods
- Plant Foods
Details on the predation ofare unknown, but common didelphid predators include owls, coyotes, foxes, and bobcats.
Through its foraging behavior,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: Positive
There are no known positive effects of this species on humans.
Economic Importance for Humans: Negative
There are no known negative consequences of this species on humans.
There is no special conservation status for (Nowak, 1997). Howver,there are reportes that most members of the genus are declining due to habitat destruction.
Nancy Shefferly (editor), Animal Diversity Web.
Aarti Mandavia (author), University of Michigan-Ann Arbor, Phil Myers (editor, instructor), Museum of Zoology, University of Michigan-Ann Arbor.
living in the southern part of the New World. In other words, Central and South America.
uses sound to communicate
young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.
Referring to an animal that lives in trees; tree-climbing.
- bilateral symmetry
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
an animal that mainly eats meat
uses smells or other chemicals to communicate
- active during the day, 2. lasting for one day.
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
An animal that eats mainly insects or spiders.
having the capacity to move from one place to another.
- native range
the area in which the animal is naturally found, the region in which it is endemic.
having more than one female as a mate at one time
- scrub forest
scrub forests develop in areas that experience dry seasons.
remains in the same area
reproduction that includes combining the genetic contribution of two individuals, a male and a female
uses touch to communicate
Living on the ground.
defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
uses sight to communicate
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
Cockrum, E. 1962. Introduction to Mammology. New York: The Ronald Press Company.
Eisenberg, J., K. Redford. 1999. Mammals of the Neotropics-Volume 3. Chicago and London: The University of Chicago Press.
Engstrom, M., B. Lim, F. Reid. 1999. "Iwokrama Mammals- Opossums. Short-tailed Opossum." (On-line). Accessed February 08, 2004 at http://iwokrama.org/mammals/frame.html.
Linares, O. 1998. Mamiferos de Venezuela. Caracas: Socieda Conservacionista Audubon de Venezuela.
NatureServe, 2003. "Didelphis brevicaudata: Red-legged, short-tailed opossum." (On-line). InfoNatura: Birds, mammals, and amphibians of Latin America. Accessed February 09, 2004 at http://www.natureserve.org/infonatura/.
Nowak, R. 1997. "Monodelphis: Short-tailed opossums" (On-line). Walker's Mammals of the World, On-Line. Accessed March 07, 2004 at http://www.press.jhu.edu/books/walkers_mammals_of_the_world/marsupialia/marsupialia.didelphidae.monodelphis.html.
Ventura, J., R. Perez-Hernandez, M. Lopez-Fuster. 1998. Morphometric Assessment of the Monodelphis brevicaudata Group in Venezuela. Journal of Mammalogy, 79/1: 104-111.
Wible, J. 2003. "The Bones of the Skull of the Short-tailed Opossum, Monodelphis brevicaudata (Didelphidae, Marsupialia)" (On-line). Accessed February 08, 2004 at http://www.carnegiemnh.org/mammals/publications/opossum.doc.
Wilson, D., D. Reeder. 1993. "Mammal Species of the World (MSW) Scientific Names" (On-line). Accessed February 07, 2004 at http://nmnhgoph.si.edu/msw/.