By Chris Gordon
Geographic Range
Didelphis albiventris is distributed throughout South America. They are found from the northern coast of Columbia south to the Patagonia mountain range in Argentina. (Talamoni and Dias, 1999)
Biogeographic Regions:
neotropical 
(native ).
Habitat
(11480 ft)
Didelphis albiventris is a habitat generalist. Individuals maintain a large home range. These animals are adapted to fluctuating conditions of rainfall, humidity, water balance, and temperature. They are found in various habitat formations such as open areas, mountains, and deciduous forest, although they are most abundant in semi-deciduous forests. (Cerqueira, 1985)
These animals are found in the following types of habitat:
temperate ; terrestrial .
Physical Description
(14.08 to 45.76 oz)
(8.46 to 13.78 in)
D. albiventris is a small mammal with black fur covering the majority of the body. The face is covered with black and white guard hairs, predominately white. The rostrum is long with whiskers present. These animals have a long, tapering tail that has a leathery appearance. Sexual size dimorphism is present in D. albiventris, with males being larger than females. Males of this species average approximatley 800 g in mass with a body length 278 mm and a tail 315 mm long. The average body mass of a female is 540 g with measurements of 249 mm and 304 mm for body length and tail length, respectively. The females also have a pouch, which is used to carry the young. (Talamoni and Dias, 1999)
Some key physical features:
endothermic ; homoiothermic; bilateral symmetry .
Sexual dimorphism: male larger.
Reproduction
These animals probably breed once or twice annually.
Breeding occurs in the rainy season.
Information on mating systems is not known. However, males of this genus are thought to be intollerant of and aggressive to one another, suggesting that females might not have the opportunity to mate with more than one male. (Nowak, 1999)
Didelphis albiventris reproduction is seasonal, but varies according to rainfall patterns. Reproduction occurs from September through May. Offspring in this genus are born very small and undeveloped. The offspring develop in the pouch of females for approximately 46 days. (Nowak, 1999; Talamoni and Dias, 1999)
The average litter size of D. albiventris is six. The size of the litter is dependent upon the age of the mother and the stage of lactation. Females become sexually mature at nine months. (Tyndale-Biscoe and Mackenzie, 1976)
Key reproductive features:
iteroparous ; year-round breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous .
Information on the parental care of this species is not available. However, it is known that within the genus, young are born incredibly undeveloped--looking more like the embryos of placental mammals than like full term infants. These young make their way into their mother's pouch, where they attach to nipples. The young complete their development in the pouch. Male parental care has not been reported. (Nowak, 1999)
Parental investment:
no parental involvement; altricial ; pre-fertilization (protecting: female); pre-hatching/birth (protecting: female); pre-weaning/fledging (provisioning: female, protecting: female); pre-independence (protecting: female).
Lifespan/Longevity
No information found on the lifespan of D. albiventris. However, within the genus. lifespan seems to fairly short. Females of the related species D. virginiana only reproduce for two seasons, and very few of that species reach more than three years of age. Although D. albiventris may live somewhat longer, it is not likely that they have a really long life. (Nowak, 1999)
Behavior
Didelphis albiventris is a nocturnal animal. During the day, these creatures find shelters to sleep in trees and other structures. (Mares and Ernest, 1995)
Species in this genus are reported to be mainly solitary, and are thought to be aggressive toward one another. This intollerance is apparently most pronounced in males. Females may be aggressive to males while they are in estrus, but males do not return the aggression. There are some reports that in captivity oppossums have friendly relationships with one another and form stable dominance heirarchies. (Nowak, 1999)
Home Range
The size of D. albiventris home ranges has not been reported.
Communication and Perception
There was not an information found on communication in D. albiventris. However, some vocalizations are known for D. virginiana including growls, hisses, skreeches, and lip clacking, which are expressed in a variety of social contexts. It is likely, that D. albiventris has similar vocalizations. As mammals, it is likely that they have some scent cues to one another. Mates as well as mothers and their offspring probably have some tactile communication. And, as they have eyes, there are probably visual signals which communicate hostility, fear, or friendly intentions which are used. (Nowak, 1999)
Food Habits
D. albiventris is an omnivorous species. During fecal analysis, scientists found invertebrates in their diet. The invertebrates consisted mainly of insects. Fruits, seeds, and vertebrates were also found to be a part of the diet of these animals. (Caceres, 2002)
One of the vertebrates consumed by D. albiventris is the pitviper Bothrops jararaca. One study showed how D. albiventris systematically attack these snakes. The opossum would kill the snake with a bite in the neck or head region. (Ermelinda Oliveira and Tadeu Santori, 1999)
Primary Diet:
omnivore .
Animal Foods:
amphibians; reptiles; insects.
Plant Foods:
seeds, grains, and nuts; fruit.
Predation
Nothing was found on predation of D. albiventris. However, larger carnivores probably feed on white-eared opossums.
Although not reported specifically for D. albiventris, other oppossums, including D. virginiana are known to "play 'possum" to avoid potential predation. In this behavior, the animals feign death, hoping that the predator will pass them by. (Nowak, 1999)
Ecosystem Roles
D. albiventris is important in the dispersal of seeds. Studies have shown that D. albiventris ingests seeds, and that the seeds of pioneer plants were not affected when passing through the digestive tract of the species. To the extent that other species prey on these animals, and to the extent that they prey on other animals, they are also an important part of food webs. (Caceres, 2002)
Key ways these animals impact their ecosystem:
disperses seeds.
Economic Importance for Humans: Negative
D. albiventris has been identified as a carrier of Sacrocystic species known to cause disease. Studies have shown that it is the carrier of at least three species: S. neurona, S. falcatula, S. speeri. (Rosenthal, Lindsay, and Dubey, 2001)
Ways that these animals might be a problem for humans:
causes or carries domestic animal disease .
Economic Importance for Humans: Positive
D. albiventris helps to maintain insect population levels. They also prey on pitvipers, which are one of the deadliest snakes in South America. (Caceres, 2002)
Ways that people benefit from these animals:
controls pest population.
Conservation Status
IUCN Red List: [link]:
Lower Risk - Least Concern.
US Federal List: [link]:
No special status.
CITES: [link]:
No special status.
Didelphis albiventris is not protected under CITES or IUCN.
Contributors
Chris Gordon (author), University of Wisconsin-Stevens Point.
Chris Yahnke (editor), University of Wisconsin Stevens Point.
Nancy Shefferly (editor), Animal Diversity Web Staff.
