Thick-tailed opossum

Lutreolina crassicaudata

SUBFAMILY

Didelphinae

TAXONOMY

Didelphis crassicaudata (Desmarest, 1804), Asunción, Paraguay.

OTHER COMMON NAMES

English: Little water opossum; French: Opossum á queue grasse; German: Dickschwanzbeutelratte; Spanish: Comadreja colorada, coligrueso.

PHYSICAL CHARACTERISTICS

Length 10–16 in (25–40 cm); weight 7–19 oz (200–540 g). The dense, soft, and relatively short hair is uniformly light cinnamon to dark brown and paler below. The legs are relatively short and the body is elongated with a long neck; the ears are short; the tail is long and almost completely furred, except for the ventral surface. There is a well-developed pouch.

DISTRIBUTION

As understood in 2002, the distribution is disjunct, with one population occurring in eastern Colombia, southern Venezuela, and Guyana, and another in eastern Bolivia, northeastern Argentina, southern Brazil, Paraguay, and Uruguay, from an altitude of 1,970–6,560 ft (600–2,000 m).

HABITAT

Found in lowland and mid-elevation tropical moist forests, grasslands, and shrublands, as well as in forest edges. Always associated with streams and rivers.

BEHAVIOR

Roosts in hollows in trees, dens of other animals, and nests constructed among the vegetation. An excellent swimmer and

also a good climber, this is a nocturnal species. It is apparently the only species of didelphid that can be accommodated in captivity in small groups, with a weak social structure that permits coexistence of two to three animals.

FEEDING ECOLOGY AND DIET

Primarily carnivorous, feeding on small vertebrates on land and in the water, as well as crustaceans, insects, and other small animals. An antibothropic biochemical factor has been isolated from its blood, indicating some level of immunity to the venom of snakes.

REPRODUCTIVE BIOLOGY

Polygamous. Gestation lasts about two weeks. Females give birth to the young in a very undeveloped state. These crawl into the pouch where they attach themselves to a nipple. Births occur twice during the year.

CONSERVATION STATUS

Not listed by the IUCN. It seems to be adaptable to a certain degree of disturbance and can be locally common in some areas.

SIGNIFICANCE TO HUMANS

Sometimes considered a nuisance because of its occasional raids on henhouses.