Shrew or rat opossum
Shrew or rat opossums are small, nocturnal mammals found primarily in the high-altitude forests of South America, particularly in the Andes Mountains. Belonging to the family Caenolestidae, they are distinct from the more commonly known possums found in Australia and surrounding regions. With a body length of three to five inches and a tail of similar length, they typically weigh between 1/2 to 1 1/2 ounces. These creatures have a soft, thick brown fur, long sensitive noses, and sharp teeth, aiding them in their diet of insects, earthworms, small invertebrates, and fruit.
Shrew opossums are solitary animals, primarily foraging along established trails. While most of their activity occurs on the ground, they are capable of climbing trees. Their habitats are often challenging to study due to the wet and cold conditions found in cloud forests, contributing to a limited understanding of their behavior and ecology. Certain species, such as the gray-bellied shrew opossum and the long-nosed caenolestid, face threats and are classified as near threatened or vulnerable by the International Union for Conservation of Nature (IUCN). Despite their elusive nature, shrew opossums play a unique role in their ecosystem, reflecting the complex biodiversity of the Andes.
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Shrew or rat opossum
Shrew or rat opossums bound and jump through the forest searching for insects and other small animals to eat.
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Paucituberculata
Family: Caenolestidae
Genus: Various (see below)
Species: Various (see below)
Shrew or rat opossums are not to be confused with other families of animals called possums. Shrew or rat opossums, as well as some members of the family of American opossums, live in South America. They have different teeth and other body features than the families of possums that live in Australia and nearby countries.
There are seven species within three genera of shrew or rat opossums. Little is known about these small creatures because they live in hard-to-reach places in the Andes Mountains from southern Venezuela to southern Chile. These opossums live on mossy slopes and ledges in high mountain forests. These forests are either wet, cold, and in the clouds, or they may be drier. The climate and conditions in these regions make them difficult to study.
Shrew or rat opossums are three to five inches (7 to 13 centimeters) long, have four- to five-inch-long (10- to 13-centimeter-long) tails, and weigh between 1/2 and 1 1/2 ounces (14 to 42 grams). They have long noses with sensitive whiskers and an excellent sense of hearing. Their eyes are small and provide poor vision. Fur is soft, thick, and brown all over their bodies. Females do not have a pouch.
Shrew opossums are nocturnal (active at night) and forage (look for food) for insects and earthworms. They also eat other small invertebrates (animals without skeletons)—like butterflies, flies, crickets, grasshoppers, and spiders—small vertebrates (animals with skeletons), and fruit. They have 46 to 48 sharp teeth for killing their prey. As they hunt, shrew opossums walk or run along well-established ground trails or runways. When they move slowly, they walk symmetrically (the same on both sides). When they want to move fast, they run, bound, and jump over obstacles without a problem. During these times, their tails help to balance and support them. Shrew opossums live alone. They spend most of their time on the ground but can climb trees.
Foxes, cats, and snakes prey on shrew opossums.
The International Union for Conservation of Nature and Natural Resources (IUCN) Red List of Threatened Species lists the gray-bellied shrew opossum and the long-nosed caenolestid as near threatened. The Andean, blackish, and eastern shrew opossum are vulnerable.
Species include:
Andean caenolestid Caenolestes condorensis
Dusky or silky caenolestid Caenolestes fuliginosus
Eastern caenolestid Caenolestes sangay
Gray-bellied caenolestid Caenolestes caniventer
Long-nosed caenolestid Rhyncholestes raphanurus
Northern or Blackish caenolestid Caenolestes convelatus
Peruvian or Incan caenolestid Lestoros inca
Bibliography
Siciliano, Martina, L. "Caenolestes Caniventer." Animal Diversity Web, animaldiversity.org/accounts/Caenolestes‗caniventer. Accessed 1 May 2024.
Siciliano, Martina, L. "Caenolestes Fuliginosus." Animal Diversity Web, animaldiversity.org/accounts/Caenolestes‗fuliginosus. Accessed 1 May 2024.