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Home -> Kingdom Animalia -> Phylum Chordata -> Subphylum Vertebrata -> Class Mammalia -> Order Didelphimorphia -> Family Didelphidae -> Subfamily Didelphinae -> Species Didelphis marsupialis

Didelphis marsupialis
southern opossum



2008/10/12 03:53:20.509 GMT-4

By Kristen Hagmann

Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Mammalia
Order: Didelphimorphia
Family: Didelphidae
Subfamily: Didelphinae
Genus: Didelphis
Species: Didelphis marsupialis

Geographic Range

The range of the southern opossum extends from eastern Mexico to northeastern Argentina (Redford and Eisenberg, 1992).

Biogeographic Regions:
neotropical (native ).

Habitat

Elevation
2232 m (high)
(7320.96 ft)


Didelphis marsupialis tolerates a variety of habitat types including primary and secondary forests, coffee plantations, urban and suburban area (Elizondo C, 1999), but are not found at elevations above 2,232 m or in arid regions. Didelphis marsupialis is replaced by its close relative, Didelphis albiventris (white-eared Opossum), in montane regions of northern South America (Eisenberg, 1989).

These animals are found in the following types of habitat:
tropical ; terrestrial .

Terrestrial Biomes:
forest ; mountains .

Physical Description

Mass
0.60 to 2.40 kg; avg. 1.50 kg
(1.32 to 5.28 lbs; avg. 3.3 lbs)


Length
263 to 450 mm; avg. 356.50 mm
(10.35 to 17.72 in; avg. 14.04 in)


Basal Metabolic Rate


There is considerable color variation in southern opossums. Generally there are varying degrees of black in the dorsal pelage, while the ventral side is white. This species is similar to D. albiventris, but has a darker dorsal pelage and black ears. Females are generally smaller than males (Cerqueira, 2000). The length of the head and body ranges from 263mm to 430 mm, with a tail length ranging from 295mm to 450 mm (Elizondo, 1999). Males are larger than females.

Some key physical features:
endothermic ; bilateral symmetry .

Reproduction

Breeding season
The mating season begins in January and ends with the onset of the dry season

Number of offspring
10 (average)

Gestation period
13.50 days (average)

Time to weaning
100 days (average)

Age at sexual or reproductive maturity (female)
8 to 12 months; avg. 10 months

Age at sexual or reproductive maturity (male)
8 to 12 months; avg. 10 months

Males mark territories more heavily with saliva prior to the breeding season. Females construct leafy nests for their new families. (Eisenberg, 1989; Eisenberg and Redford, 1992) Mating is most likely polygynous, with males mating those females present in their territories.

Mating systems:
polygynous .

Mating season begins in January, with males marking their home range more heavily with saliva and females building leaf nests in tree cavities or burrows. In captivity it has been reported that females can have an average litter size of ten, and up to three litters have been reported in one year. Also, the smallest litter sizes are found near the equator.

The young are born naked and blind and on average weigh about 0.005 oz and measure 10 mm in length. This amazingly small body size means that twenty four newborns can fit into a teaspoon! The newborns must find their way to their mother's marsupium or pouch. They can only move with their forelegs, which are more developed than their hind legs. There are two theories as to how the newborns find their way to the marsupium. The first, and best supported, theory is that newborns find their way to the marsupium by smell. Before birth the mother will lick a path to the opening of the pouch so that the young can follow the trail. The second theory is that the young find their way to the pouch through gravity. Once the newborns have found the marsupium, they attach to the teats, which then swell at the tip preventing the newborns from falling off. The young grow rapidly and are ready to leave the marsupium after about sixty days. (Parker, 1990)

The young are weaned around 100 days. The young reach sexual maturity between 8 and 12 months of age. (Eisenberg, 1989; Eisenberg and Redford, 1992)

Key reproductive features:
iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization ; viviparous .

The female cares for the young in her marsupium, or pouch, for 60 days. The young are not weaned until they are about 100 days old. (Eisenberg, 1989; Eisenberg and Redford, 1992)

Parental investment:
altricial ; female parental care .

Lifespan/Longevity

Average lifespan (wild)
2 years

Extreme lifespan (captivity)
7 years (high)

Average lifespan (captivity)
4.20 years
[External Source: AnAge]


These animals probably do not live that long in the wild. It has been reported that they usually live about two years in their natural habitat, but they can live up to seven years in captivity.

Behavior

Didelphis marsupialis is solitary except during the breeding season. These opossums navigate mainly by olfaction and touch. They climb well but frequently forage on the ground, and seek refuge in hollow trees, a den under roots, or holes in the ground. They do not actively defend a specific area or territory. When home ranges overlap, each animal (usually males) will mark the area with urine, droppings and saliva. Southern opossums typically avoid one another, and if males come into contact, they become aggressive. Threatening behavior begins with the mouth opening, and is followed by hissing, growling, and finally snapping. Females are more sedentary than males. Southern opossums can't maintain body warmth below an environmental temperature of minus seven degrees celsius. During cold spells, these opossums will sleep in dens, but they do not hibernate. (Eisenberg, 1989)

Key behaviors:
arboreal ; terricolous; nocturnal ; crepuscular ; motile ; sedentary ; solitary .

Food Habits

Southern opossums are omnivorous and will eat a large variety of food. In captivity they especially like bananas. They are opportunistic feeders and will readily shift home ranges in search of food. Feeding habits of males and females do not differ significantly, but there are differences in food preferences between young and old. Younger individuals primarily consume invertebrates, fruits, and plant remains, whereas older individuals consume all of these, as well as mammals and birds.

Foods eaten include: insects, frogs, birds, small mammals, earthworms, fruits and plant remains.

(Cordero and Nicolas, 1987)

Primary Diet:
omnivore .

Animal Foods:
birds; mammals; amphibians; insects; terrestrial worms.

Plant Foods:
fruit.

Predation

Known predators

The most well-known adaptation for evading predators is known as "playing dead" or "playing opossum." An opossums will lie on its side as if dead with its tails rolled up, eyes and mouth open, and its paws partially closed. (Parker, 1990) Common predators of southern opossums include owls, snakes, and mammalian carnivores.

Ecosystem Roles

Didelphis marsupialis plays an important role in food webs. Because of its feeding habits, this species is likely to be important in controlling populations of small mammals and invertebrates. Because it is a prey species, it also plays an important role in regulating populations of owls and small, mammalian carnivores.

Economic Importance for Humans: Negative

In Venezuela, D. marsupialis is an important host for the parasite Trypanosoma cruzi, which is the source for the human illness known as Chagas Disease (Eisenberg, 1989).

Economic Importance for Humans: Positive

No reported positive effects on humans exist.

Conservation Status

IUCN Red List: [link]:
Lower Risk - Least Concern.

US Federal List: [link]:
No special status.

CITES: [link]:
No special status.

This species has no special conservation status.

Contributors

Kristen Hagmann (author), University of Wisconsin-Stevens Point.
Chris Yahnke (editor), University of Wisconsin Stevens Point.

References

Boyett, W., M. Endries, G. Adler. 2000. Colonization-extinction dynamics of opossums on small islands in Panama. Canadian Journal of Zoology, 78: 1972-1979.

Cerqueira, R., B. Lemos. 2000. Morphometric differentiation between Neotropical black-eared opossums and *D. aurita*. Mammalia, 64: 319-327.

Cordero, G., R. Nicolas. 1987. Feeding habits of the opossum (*Didelphis marsupialis*) in northern Venezuela. Fieldiana: Zoology, Studies in Neotropical Mammalogy, 39: 125-131.

Eisenberg, J., K. Redford. 1989. Mammals of the Neotropics, the Northern Neotropics. Chicago: University of Chicago Press.

Elizondo C, L. 1999. "Instituto Nacional de Biodiversidad" (On-line). Accessed October 28, 2001 at http://www.inbio.ac.cr/bims/ubi/mamiferos/ubiespejo/ubiid=1483&-find.html.

Parker, . 1990. Grzimek's Encyclopedia of Mammals. New York: McGraw Hill Publishing Company.

Redford, K., J. Eisenberg. 1992. Mammals of the Neotropics, the Southern Cone. Chicago: University of Chicago Press.

2008/10/12 03:53:22.797 GMT-4

To cite this page: Hagmann, K. 2003. "Didelphis marsupialis" (On-line), Animal Diversity Web. Accessed October 12, 2008 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Didelphis_marsupialis.html.

Disclaimer: The Animal Diversity Web is an educational resource written largely by and for college students. ADW doesn't cover all species in the world, nor does it include all the latest scientific information about organisms we describe. Though we edit our accounts for accuracy, we cannot guarantee all information in those accounts. While ADW staff and contributors provide references to books and websites that we believe are reputable, we cannot necessarily endorse the contents of references beyond our control.

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