The black-shouldered opossum (''Caluromysiops irrupta''), also known as the white-eared opossum, is an

opossum Opossums () are members of the marsupial order Didelphimorphia () endemic to the Americas. The largest order of marsupials in the Western Hemisphere, it comprises 126 species in 18 genera. Opossums originated in South America and entered North A ...

known from western

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

and southeastern

Peru Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...

. It was first described by Colin Campbell Sanborn, curator of Field Museum of Natural History, in 1951. The black-shouldered opossum is characterized by a gray coat, gray underbelly, and broad black stripes that extend from the forefeet, meet on the shoulders, run along the midline of the back and then split into parallel stripes that run down the hind feet. Little is known of the behavior of the black-shouldered opossum. It is

nocturnal Nocturnality is a ethology, behavior in some non-human animals characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnality, diurnal meaning the opposite. Nocturnal creatur ...

and

arboreal Arboreal locomotion is the locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally (scansorial), but others are exclusively arboreal. The hab ...

. It is known to feed on fruits and rodents. The opossum inhabits humid forests. The

IUCN The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...

classifies it as

least concern A least-concern species is a species that has been evaluated and categorized by the International Union for Conservation of Nature (IUCN) as not being a focus of wildlife conservation because the specific species is still plentiful in the wil ...

Taxonomy

The black-shouldered opossum is the sole member of ''Caluromysiops'', and is placed in the family Didelphidae. No subspecies are recognized. The

cladogram A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ...

below, based on a 2016 study, shows the

phylogenetic In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical dat ...

relationships of the brown-eared woolly opossum.

Description

The black-shouldered opossum is characterized by a gray coat, gray underbelly with buff-tipped hairs, and broad black stripes that extend from the forefeet, meet on the shoulders, run along the midline of the back and then split into parallel stripes that run down the hindfeet. Indistinct dark lines run through the eyes. 60 to 75 percent of the length of the tail is darker than the coat dorsally (on the back), while the rest is white. Except for the last 75 percent of the length at the base, the tail is bushy. Like '' Caluromys'' species, its fur is soft, thick and woolly, and has a similar skull. However, it differs from them in having a shorter rostrum and larger molars. The head-and-body length is between and the tail measures . The hindfeet measure , while the ears .

Ecology and behavior

The black-shouldered opossum's behavior is not well documented. It is

and

. It spends a significant amount of time in trees, mainly on high branches. Studies suggest individual diet preferences; the opossums feed on rodents as well as fruits. Lifespan in captivity has been known to exceed seven years. Up to two young have been recorded.

Distribution and status

The black-shouldered opossum occurs in humid forests of western

and southeastern

, and probably in

Bolivia Bolivia, officially the Plurinational State of Bolivia, is a landlocked country located in central South America. The country features diverse geography, including vast Amazonian plains, tropical lowlands, mountains, the Gran Chaco Province, w ...

as well. There are also reported sightings near the Peru-

Ecuador Ecuador, officially the Republic of Ecuador, is a country in northwestern South America, bordered by Colombia on the north, Peru on the east and south, and the Pacific Ocean on the west. It also includes the Galápagos Province which contain ...

border, but these are most likely based on captives. It is known only from five different localities. The

classifies it as

given its wide distribution and presumably large population. A possible threat to its survival is deforestation.

References

External links

* {{Taxonbar, from=Q301041 Mammals described in 1951 Marsupials of Brazil Marsupials of Peru Opossums Taxa named by Colin Campbell Sanborn