Because this species is small and nocturnal, communication between individuals is likely primarily olfactory in nature. Palma (1997) reports that the olfactory and visual regions of this species' brain are especially well developed.
Communication Channels: visual ; tactile ; acoustic ; chemical
Perception Channels: visual ; tactile ; acoustic ; chemical
Thylamys elegans is considered "least concern" by the IUCN.
IUCN Red List of Threatened Species: least concern
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
This species likely has little direct impact on humans.
This species likely has little direct impact on humans.
Thylamys elegans acts as an important predator of many arthropod species and some small vertebrates. It is prey to several bird and medium-sized mammals, such as owls and foxes. It is likely host to many ecto- and endoparasites. More specific information about the ecosystem role of Thylamys elegans is not presently available.
Like other Thylamys species, Thylamys elegans primarily consumes insects, although it occasionally eats small vertebrates, leaves, fruit, seeds, and carrion (Palma 1997).
Animal Foods: birds; mammals; amphibians; reptiles; carrion ; terrestrial non-insect arthropods
Plant Foods: leaves; seeds, grains, and nuts; fruit
Primary Diet: carnivore (Insectivore )
Thylamys elegans appears to be restricted to central Chile, but further surveys are needed to determine the limits of its distribution (Giarla et al., 2010).
Biogeographic Regions: neotropical (Native )
Thylamys elegans primarily inhabits the Chilean Matorral, an ecoregion characterized by a Mediterranean climate and sclerophyllous vegetation. The Atacama desert lies to the north of the Matorral, and Thylamys elegans might inhabit parts of this habitat as well.
Range elevation: 0 to 1000 m.
Habitat Regions: temperate ; terrestrial
Terrestrial Biomes: desert or dune ; chaparral ; scrub forest
No published records of lifespan exist for this species.
Like other members of its genus, Thylamys elegans is notable for its incrassate (fattened) tail. The size of the tail varies by season in accordance with food availability. This species is tricolored, with darker dorsal fur, paler lateral fur, and a cream-colored ventral region. Giarla et al. (2010) report body lengths of 90 to 127 mm, with tails 105 to 134 mm long. Although this species is a marsupial, females do not have a pouch (Palma, 1997). Bozinovic et al. (2005) report a basal metabolic rate of 1.07 mL oxygen per gram-hour-ºC
Range length: 195 to 261 mm.
Average basal metabolic rate: 1.07 cm3.O2/g/hr.
Other Physical Features: endothermic ; bilateral symmetry
Like other small mammals, Thylamys elegans is likely well adapted to avoiding predators by being nocturnal and inconspicuous.
Known Predators:
Anti-predator Adaptations: cryptic
Little is known about the mating system in Thylamys elegans. Palma (1997) reports that two adults have never been found in the same nest, suggesting that this species does not form monogamous breeding pairs.
Breeding season for Thylamys elegans occurs from September through March, with females having one or two litters per season. Up to 17 embryos have been reported, but survival is limited by the number of functional nipples on the female, which is typically 11 to 13 (Palma, 1997).
Breeding interval: Thylamys elegans has one or two litters per breeding season
Breeding season: Breeding occurs from September to March.
Range number of offspring: 17 (high) .
Average number of offspring: 12.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous
Little is known about parental care in Thylamys elegans. Like other Thylamys species, females lack a pouch and exposed young cling to the nipples.
Parental Investment: altricial ; female parental care ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Protecting: Female)
The elegant fat-tailed mouse opossum (Thylamys elegans), also known as the Chilean mouse opossum, is an opossum from central Chile. The type species of Thylamys, it was first described by English naturalist George Robert Waterhouse in 1839. This medium-sized opossum is characterized by black rings around the eyes, white limbs, gray to light brown coat, lighter flanks and underbelly and a thick 12.7–14.6 centimetres (5.0–5.7 in) long tail covered with hairs. It is crepuscular (active mainly around twilight) and lives in nests in tree hollows or under rocks and roots. This opossum feeds mainly on arthropods and larvae apart from fruits. Litter size is typically between 11 and 13. The elegant fat-tailed opossum can occur in a variety of habitats – from cloud forests to chaparrals. The IUCN classifies the opossum as least concern.
The elegant fat-tailed mouse opossum is the type species of Thylamys, and is placed in the family Didelphidae. It was first described by English naturalist George Robert Waterhouse as Didelphis elegans in 1839. It was given its present binomial name by English zoologist John Edward Gray in 1843.[3][4]
The cladogram below, based on a 2016 study, shows the phylogenetic relationships of the elegant fat-tailed mouse opossum.[5]
Patagonian opossum (Lestodelphys halli)
ThylamysDwarf fat-tailed mouse opossum (T. velutinus)
Karimi's fat-tailed mouse opossum (T. karimii)
Buff-bellied fat-tailed mouse opossum (T. venustus)
Cinderella fat-tailed mouse opossum (T. cinderella)
Argentine fat-tailed mouse opossum (T. sponsorius)
Paraguayan fat-tailed mouse opossum (T. macrurus)
Tate's fat-tailed mouse opossum (T. tatei)
Elegant fat-tailed mouse opossum (T. elegans)
White-bellied fat-tailed mouse opossum (T. pallidior)
T. citellus
T. pulchellus
Common fat-tailed mouse opossum (T. pusillus)
The generic name is composed of the Greek words thylas ("pouch") and mys ("mouse"), and the specific name elegans means "elegant" in Latin. Alternate names for this mouse opossum include Chilean mouse opossum,[6] comadreja, llaca, marmosa chilena, marmosa elegante and yaca.[2]
The elegant fat-tailed mouse opossum is a medium-sized opossum characterized by white limbs, gray to light brown coat, lighter flanks and underbelly, and a thick 12.7–14.6 centimetres (5.0–5.7 in) long tail covered with hairs. A prominent facial feature is the black ring around either eye; the rings slightly extend toward the nose. The coat color varies geographically.[7] The tail can thicken due to accumulation of fat; the diameter of the tail can reach 1 centimetre (0.39 in) where it is connected to the body.[8] The head-and-body length is 11–13.7 centimetres (4.3–5.4 in); the hindfeet measure 1.7 centimetres (0.67 in), while ears measure 2.3 centimetres (0.91 in).[2]
This opossum can exhibit torpor, a mechanism that allows the opossum to significantly reduce its food and energy requirements. This is similar to hibernation, except that it is only done for a short period of time.[9] Additionally, when water is scarce, the urine tends to become very concentrated.[2]
The elegant fat-tailed mouse opossum is crepuscular (active mainly around twilight).[1] It lives in nests (abandoned by birds and rodents, or built by itself) in tree hollows, under rocks and roots. It is arboreal (tree-living) as well as terrestrial (land-living). The opossum feeds mainly on arthropods and larvae, along with fruits, small vertebrates and carrion.[7] This opossum can use its prehensile tail, regardless of its thickness, to efficiently climb and grasp branches – an ability not as developed in other small Chilean mammals.[10] Nests are generally occupied by one individual; in southern Chile, the home range of this opossum is 1,383 square metres (14,890 sq ft) large in July, and shrinks to 781 square metres (8,410 sq ft) in December.[11] Predators of this opossum include the culpeo fox, burrowing owl and the great horned owl.[2]
Both sexes mature by the first year. A female can have one to two litters in the annual breeding season, typically from September to March.[2] Up to 17 embryos can be produced,[12] but the number of survivors will depend on the number of nipples functioning (typically 11 to 13).[2]
The elegant fat-tailed mouse opossum occurs in a variety of habitats – from cloud forests to chaparrals, up to an altitude of 2,500 metres (8,200 ft) above the sea level. It occurs to the west of the Andes in central Chile. The IUCN lists this opossum as least concern given its wide distribution and presumably large numbers, but deforestation and agricultural expansion have led to decline in populations in some parts of the range.[1]
The elegant fat-tailed mouse opossum (Thylamys elegans), also known as the Chilean mouse opossum, is an opossum from central Chile. The type species of Thylamys, it was first described by English naturalist George Robert Waterhouse in 1839. This medium-sized opossum is characterized by black rings around the eyes, white limbs, gray to light brown coat, lighter flanks and underbelly and a thick 12.7–14.6 centimetres (5.0–5.7 in) long tail covered with hairs. It is crepuscular (active mainly around twilight) and lives in nests in tree hollows or under rocks and roots. This opossum feeds mainly on arthropods and larvae apart from fruits. Litter size is typically between 11 and 13. The elegant fat-tailed opossum can occur in a variety of habitats – from cloud forests to chaparrals. The IUCN classifies the opossum as least concern.
