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.
Mating System: 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.
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.
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.
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.
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 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.
Key Reproductive Features: gonochoric/gonochoristic/dioecious (sexes separate); viviparous
Average number of offspring: 7.
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.
Parental Investment: no parental involvement; altricial ; pre-fertilization (Protecting: Female); pre-hatching/birth (Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female)
- Cockrum, E. 1962. Introduction to Mammology. New York: The Ronald Press Company.
- Linares, O. 1998. Mamiferos de Venezuela. Caracas: Socieda Conservacionista Audubon de Venezuela.
- 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.