Patagonian opossums ( (Marshall, 1977)) occur farther south than any other known living marsupial species. They are endemic to Argentina, particularly in the Patagonian pampas, Chubet, Mendoza, Neuquen, Rio Negro and Santa Cruz.
Patagonian opossums are terrestrial, although they have been trapped on tree branches. They occur mainly in areas of shrubs, grasslands, meadows and savannahs. These animals are often found in dry and cold areas of Patagonia. (Marshall, 1977; Martin and Sauthier, 2011; Martin, 2005; New World Marsupial Specialist Group, 2006; Pearson, 2008)
Patagonian opossums have short, soft, dense pelage. Their dorsal pelage is dark gray, their ventral pelage and paws are white. Patagonian opossums have white patches over their eyes and black rings encircling their eyes. Their rostrums are short, but their cheeks are wide. Their head to body lengths range from 132 to 144 mm. Their semi-prehensile tails have short grayish fur dorsally and whitish fur ventrally and are between 81 to 99 mm long, about 75% of their head to body length. Their hind feet have an opposable hallux and are between 15.7 and 17.7 mm long. Their ears are round and short, about 18 to 22 mm in length. They have extremely long, straight canines. Their dental formula is: I 5/4, C 1/1, P 3/3, M 4/4. (Marshall, 1977; Martin and Sauthier, 2011; Pearson, 2008)
There is little available information on the mating systems of Patagonian opossums. It is likely that males and females only loosely associate for mating and that mating is polygynous, as it is in other didelphids. (Fernandes, et al., 2010; O'Connell, 2006)
Female Patagonian opossums have 19 mammae. Examination of prepared museum skins revealed that these animals do not have a pouch. Like all marsupials, they have a relatively short gestation period followed by a lengthy period of lactation. Little information is available on their reproduction; however, based on observations of wild individuals, certain assumptions can be made. Solitary juvenile Patagonian opossums have been found in autumn, which has led researchers to believe that at least some individuals become independent in the fall. Furthermore, it is likely that independence coincides with prey abundance, in summer and early fall. If this is accurate, this species may breed seasonally, with only one breeding season per year. (Birney, et al., 1996; Redford and Eisenberg, 1992)
There is little information available on parental investment in Patagonian opossums. Similar to other didelphids, these animals likely have extremely altricial young that nurse until independence. (O'Connell, 2006)
Patagonian opossums live in areas with long, hard winters. They forage under the snow for rodents and enter periods of torpor to survive spans of low food availability or extreme cold. In such cases, they enter a torpid state typically lasting 2 to 7 hours; however, it may last as long as 4 days. These opossums accumulate fat at the base of their tails as a food store during lean times. Their tail thickness varies noticeably based on their feeding frequency. They walk with a plantigrade stance and use their long claws to dig for food or shelter. These animals are also adept climbers and jumpers. In a captive study, both genders created nests from a variety of substrates. Like other related opossums, they are mainly nocturnal and solitary. Unlike most didelphids when conspecifics were housed together in a captive environment, they were not aggressive. (Martin and Sauthier, 2011; Nowak, 1999; Redford and Eisenberg, 1992)
There is no information available on the home range of Patagonian opossums. (New World Marsupial Specialist Group, 2006)
There is little information available on the communication and perception of Patagonian opossums. However, when these animals perceive a threat they may take a bipedal stance and produce a series of high-pitched screams. They are also known to leave their mouth ajar and snap their teeth when they are vulnerable. (Martin and Sauthier, 2011)
Patagonian opossums are primarily carnivorous, as opposed to most didelphids, which are omnivorous. Their diet consists mainly of small birds and rodents. A 70 gram animal has been observed eating a 35 gram mouse. Patagonian opossums have also been captured in traps baited with dead birds. These animals have short skulls, with long claws and teeth, all features classically possessed by carnivores. These opossums will also eat fruits and insects where they are available. However, in a captive study, these animals preferred live vertebrate prey over other food options. During winter months, they may hunt under the snow or go into torpor. They also store fat at the base of their tails. (Marshall, 1977; Martin and Sauthier, 2011; Nowak, 1999; Redford and Eisenberg, 1992)
Scientific studies with barn owls (Tyto alba) and Magellanic horned owls (Bubo magellanicus) have recovered pellet samples containing remnants of Patagonian opossums. They may also serve as a food source to humans. (Martin, 2005)
Patagonian opossums are significant prey items for barn (Tyto alba) and Magellanic horned owls (Bubo magellanicus), their pellet remains have been collected from roosting and nesting sites. Patagonian opossums are also predators of small rodents and birds in their ecosystems. (Martin, 2005; Nowak, 1999)
Patagonian opossums often live in close proximity to human dwellings. Due to their carnivorous food preferences, they likely help control rodent populations. This may have a positive economic impact because rodents often destroy farmer's crops and carry many diseases. (Macdonald, 2001)
There is little information on negative economic impacts of Patagonian opossums.
Patagonian opossums are experiencing habitat loss and degradation in some of their preferred habitats, which are extensively modified for agriculture. They were classified as vulnerable in 1996 by the IUCN, but are currently listed as a species of least concern in 2013. (Costa, et al., 2008; New World Marsupial Specialist Group, 2006)
Patagonian opossums were previously known by the name Notodelphys halli. They are also known as Opossum De Patagonie. (Marshall, 1977)
Leila Siciliano Martina (author), Animal Diversity Web Staff.
John Preuss (author), University of Wisconsin-Stevens Point, Chris Yahnke (editor, instructor), University of Wisconsin-Stevens Point.
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.
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
Found in coastal areas between 30 and 40 degrees latitude, in areas with a Mediterranean climate. Vegetation is dominated by stands of dense, spiny shrubs with tough (hard or waxy) evergreen leaves. May be maintained by periodic fire. In South America it includes the scrub ecotone between forest and paramo.
uses smells or other chemicals to communicate
active at dawn and dusk
having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.
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.
having the capacity to move from one place to another.
the area in which the animal is naturally found, the region in which it is endemic.
active during the night
breeding is confined to a particular season
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.
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.
A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.
A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.
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.
Birney, E., J. Monjeau, C. Phillips, R. Sikes, I. Kim. 1996. Mastozoologia Neotropical, 3:2: 171-181.: New information on a poorly known Argentine mammal.
Costa, L., D. Astua de Moraes, D. Brito, P. Soriano, D. Lew, C. Delgado. 2008. "www.iucnredlist.org." (On-line). IUCN Red List of Threatened Species. Accessed May 26, 2013 at
Fernandes, F., L. Cruz, E. Martins, S. dos Reis. 2010. Growth and home range size of the gracile mouse opossum Gracilinanus microtarsus (Marsupialis:Didelphidae) in Brazilian cerrado. Journal of Tropical Ecology, 26:2: 185-192.
Formoso, A., D. Sauthier, P. Teta, U. Pardinas. 2011. Dense-sampling reveals a complex distributional pattern between the southernmost marsupials Lestodelphys and Thylamys in Patagonia, Argentina. Mammalia, 75: 371-379.
Macdonald, D. 2001. The Encyclopedia of Mammals. Oxfordshire, United Kingdom: Andromedia Oxford Limited.
Marshall, L. 1977. Mammalian Species. University of California, Berkeley: The American Society of Mammalogists.
Martin, G. 2005. Intraspecific variation in Marsupialia: Didelphimorphia). Journal of Mammalogy, 86/4: "793-802".(
New World Marsupial Specialist Group, 2006. "The IUCN Red List of Threatened Species" (On-line). Accessed November 01, 2006 at http://www.iucnredlist.org.
Nowak, R. 1999. Walker's Mammals of the World, Sixth Edition Volume One. Baltimore and London: The Johns Hopkins University Press.
O'Connell, M. 2006. American opossums. Pp. 808-813 in D MacDonald, S Norris, eds. The Encyclopedia of Mammals, Vol. 1. London: The Brown Reference Group.
Pearson, O. 2008. Genus Lestodelphys. Pp. 50-51 in A Gardner, ed. Mammals of South America: Marsupials, Xenarthrans, Shrews, and Bats, Vol. 1. Chicago: University of Chicago Press.
Redford, K., J. Eisenberg. 1992. Mammals of the Neotropics - The Southern Cone Volume 2. United States of America: University of Chicago Press.