Geographic Range
Patagonian opossums (
Lestodelphys halli
) 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.
- Biogeographic Regions
- neotropical
Habitat
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.
- Habitat Regions
- tropical
- terrestrial
- Terrestrial Biomes
- savanna or grassland
- chaparral
Physical Description
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.
- Other Physical Features
- endothermic
- bilateral symmetry
Reproduction
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
.
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.
- Key Reproductive Features
- seasonal breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- viviparous
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.
- Parental Investment
- altricial
Lifespan/Longevity
There is little information available on the longevity of Patagonian opossums. However,
most
didelphid
species live approximately 1 to 2 years.
Behavior
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.
- Key Behaviors
- terricolous
- nocturnal
- crepuscular
- motile
- sedentary
- solitary
Home Range
There is no information available on the home range of Patagonian opossums.
Communication and Perception
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.
Food Habits
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.
- Primary Diet
-
carnivore
- eats terrestrial vertebrates
- Animal Foods
- birds
- mammals
- insects
- Plant Foods
- fruit
Predation
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.
- Anti-predator Adaptations
- cryptic
Ecosystem Roles
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.
Economic Importance for Humans: Positive
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.
- Positive Impacts
- controls pest population
Economic Importance for Humans: Negative
There is little information on negative economic impacts of Patagonian opossums.
Conservation Status
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.
Other Comments
Patagonian opossums were previously known by the name
Notodelphys halli
. They are also known as
Opossum De Patagonie
.
Additional Links
Contributors
Leila Siciliano Martina (author), Texas State University.
John Preuss (author), University of Wisconsin-Stevens Point, Chris Yahnke (editor, instructor), University of Wisconsin-Stevens Point.
- Neotropical
-
living in the southern part of the New World. In other words, Central and South America.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- tropical
-
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
- terrestrial
-
Living on the ground.
- tropical savanna and grassland
-
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.
- savanna
-
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.
- temperate grassland
-
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.
- chaparral
-
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.
- seasonal breeding
-
breeding is confined to a particular season
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- viviparous
-
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
- altricial
-
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.
- nocturnal
-
active during the night
- crepuscular
-
active at dawn and dusk
- motile
-
having the capacity to move from one place to another.
- sedentary
-
remains in the same area
- solitary
-
lives alone
- visual
-
uses sight to communicate
- acoustic
-
uses sound to communicate
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- acoustic
-
uses sound to communicate
- chemical
-
uses smells or other chemicals to communicate
- cryptic
-
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.
- carnivore
-
an animal that mainly eats meat
- endothermic
-
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.
- 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.
References
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