The opossum (Didelphimorphia) is a medium-sized terrestrial marsupial with long naked tail. In the Western Hemisphere they make up the largest marsupial order. They are semi-arboreal species and most of them are omnivores. Opossums are found in the dry and moist tropical forests of the North America ranging from southern Canada to as far as southern Argentina.
- Opossums have long pointed snout along with the opposable thumbs in the hands and feet. Some of the opossums are one-colored species while others display unique dark bands.
- The length averages 3–22 in (8–55 cm) and weighs up to 0.9 oz–11 lb (25–5,000 g).
- Some species possesses tail completely covered with hair, others have long naked tail. Typically the length of the tail is greater than its entire body length.
- Water opossum has webbed feet which helps the animal in swimming. They are excellent swimmers.
- There are 103 opossum species and all of them are of different colors. Some of them are uniformly blackish whereas others seem to be completely whitish, still others display rusty reddish, gray, brown, tan, or yellowish brown.
- Opossum’s hair can be long or short depending on the species but it is always dense. Some females have pouchs that opens circularly while others have absolutely closed pouchs.
- Opossums belonging to the family Didelphidae, are found only in the New World, ranging from Patagonian Argentina, southern Canada, north Chile, to the northeastern United States.
- They are widely distributed in the tropical and subtropical forests between Argentina and Mexico except for Virginia opossum which is mainly found in the United States and Canada. It is the most common species in the entire family.
- The opossum makes home in a variety of habitats ranging from cloud forests, dry tropical forests, scrubs, grasslands, mangroves, and to the temperate forests.
- Latrine opossums (Lutreolina crassicaudata) are known to breed in the South American grasslands, pampas, including lakes and streams. Virginia opossums are the remarkable swimmers. Yet another species water opossum also lives in moist forests such as lakes.
- Many opossum species are expert tree climbers and they are equally good moving on the ground. Some species reach the top of the forest canopy trees. Few of the opossums are primarily terrestrial species.
- Opossums have evolved to adapt many different habitats at almost every latitude from sea level to as high as 13,100 ft (4,000 m) above sea level.
- Many species however have a limited habitat range. Common opossums and Virginia opossums are known to breed in diverse habitats.
- Opossums have also occupied much of the agricultural land including corn fields, citrus plantations, coffee, and banana. A few species makes habitats in forest edges and secondary vegetation.
- Nearly all opossum species are nocturnal with only a few specimen are seen during the day.
- Opossums are generally very slow runners even when the predators are after them. They do however produce loud hissing sounds to run off their predators.
- They love to dive under the water surface. Opossum propels itself by giving strong strokes from hind legs.
- Almost all species are solitary prefer to stay alone. They never defend their territories. When two individuals come face to face they avoid each other.
- Older, heavier adults are thought to dominate younger ones.
- Opossums are silent and never produce sounds unless they are threatened. They largely use sense of smell to locate food. They rarely stalk animal prey. Young individuals typically emit a loud chirping cry.
- Predators of opossums include a variety of snakes, foxes, owls, ocelot (Leopardis pardalis), puma (Puma cencolor), and jaguar (Panthera onca).
- The average lifespan in captivity is 3 – 5 years.
Feeding Ecology and Diet
- Opossums are almost exclusively omnivores as they readily feed on insects, insect larvae, worms, bird’s eggs and nestlings, fruit, carrion, reptiles, amphibians, birds, and small mammals.
- However many species have frugivorous and carnivorous diet. Caluromys and Caluromysiops are exclusively frugivorous but they do supplement their diet with some animals.
- Species in the genera Marmosa, Marmosops, Gracilinanus are thought to be insectivorous but they also consume meat, eggs, and fruits.
- In captivity mouse opossums are most likely to eat large grasshoppers, caterpillars and moths. They eat the whole insect leaving away its legs and wings. They roll and rub caterpillars to get rid of their hairs.
- They are also known to eat fruits either from the branches or simply from fallen fruits.
- In captivity, opossums fancy drinking juicy fruits for e.g. zapotes, blackberries, guavas, chirimoyas. The captive animals will not hesitate to feed on wild figs, cocoa, citrus fruits, cherries, apples, and bananas.
- Four-eyed and common opossums are likely to consume large amount of fruits int eh secondary forest.
- The only carnivorous marsupial in the New World is the water opossum (Chironectes minimus) that primarily feeds on fish, crustaceans, mollusks, and frogs.
- Nearly all opossums have short gestation period lasting 12 – 15 days.
- Young opossums become independent after 2 – 4 months.
- 5 – 12 young are born in Monodelphis, 2 – 5 in Caluromys, 4 – 12 in Marmosa, 2 – 5 in Chironectes, in Didelphis the average number of offspring is 6 – 15, and in Philander it ranges from 1 – 9.
- Depends on the genera, opossums attain maturity at 3 – 9 months.
- Opossums build nests not only on the standing trees but also on the fallen ones.
- Critically Endangered: 3 species
- Endangered: 3 species
- Vulnerable: 15 species
- Near Threatened: 18 species
- Data Deficient: 2 species
Collins, L. Monotremes and Marsupials. Washington, DC: Smithsonian Institution Press, 1973
Hunsaker II, D. The Biology of Marsupials. New York: Academic Press, 1977.
Nowak, R. M. Walker’s Mammals of the World. 6th ed., Vol. 1, Baltimore: John Hopkins University Press, 1999.
Castro, I., H. Zarza, and R. A. Medellín. “Philander opossum.” Mammalian Species 638 (2000): 1–8.
Alonso-Mejía, A., and R. A. Medellín. “Marmosa mexicana.” Mammalian Species 421 (1992): 1–4.