Communication in African Forest shrews is limited. Nesting pairs chatter to each other, and when alarmed or fighting, they may produce a sharp squeak. Forest shrews rely on acoustic, visual, tactile, and chemical cues to perceive their environment. Courting behavior between potential mates consists of a males chasing and catching mates by the nape. Males rely on their sense of smell to determine whether a female is in estrus or not.
Communication Channels: acoustic ; chemical
Perception Channels: visual ; tactile ; acoustic ; chemical
Myosorex varius is categorized as a species of least concern by the IUCN's Red List of Threatened Species and all other known conservation organizations. Population trends are stable, and there are no major threats to the long-term persistence of this species.
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
IUCN Red List of Threatened Species: least concern
There are no known adverse effects of Myosorex varius on humans.
As an insectivore, Myosorex varius likely helps control insect pest species throughout its geographic range.
Positive Impacts: controls pest population
Myosorex varius acts as prey to numerous larger mammals. It also serves as a predator to insects and other invertebrates, and as a result, may help control insect pest species. It also acts as a scavenger and eats carrion from dead rodents and conspecifics. It creates creates habitat via shallow burrows in the soil and under rocks. Disturbing soil helps to release nitrogen contents to the surface of the soil, allowing for a diversity of plants to grow. Parasites of this species have not been documented.
Ecosystem Impact: creates habitat
Myosorex varius is insectivorous. It is considered an opportunistic feeders and eats most invertebrates it encounters. Evidence suggests that it feeds on at least 7 different types of arthropods including crustaceans, millipedes and centipedes, and arachnids. It frequently drinks small amounts of water. When eating small prey, it first beheads the arthropod and then rapidly bites the insect down the abdomen before beginning to actually eat the animal. When consuming large prey, M. varius throws the insect into the air and breaks off any legs or hind limbs by jerking or twisting them off and then beheads and bites the insect. Cannibalism has been documented in M varius and occasionally consumes carrion of conspecifics or rodents. In captivity, it has been known to eat plants, however, this has never been observed in wild populations.
Animal Foods: mammals; insects; terrestrial non-insect arthropods; aquatic crustaceans
Plant Foods: leaves
Primary Diet: carnivore (Insectivore , Scavenger )
Myosorex varius is a forest shrew that is native to the Ethiopian region of the world. The shrew is endemic to the southern portion of Africa. Of all the 15 different species of South African forest shrews, M. varius is one of the most widely distributed species. It can be found in Limopopo Province, Gauteng, Mpumalanga, the north-eastern Free State, throughout KwaZulu-Natal, Eastern and Western Cape, where M. varius is found inland to Murraysberg and Beaufort West, as well as coastally from Western Cape to the northwestern parts of North Cape. They are found as far north as Pot Nolloth. This species is also found in Lesotho and the Highveld and Middleveld regions of Swaziland. The areas encompass much of the southern region of Africa. Myosorex varius is sympatric throughout much of its geographic range with Myosorex cafer.
Biogeographic Regions: ethiopian (Native )
Myosorex varius is a terrestrial mammal that can be found at elevations ranging from sea level to 1,740 m of elevation. It is called the forest shrew because it is most often found in forest habitats. Myosorex varius can be found in moist, densely vegetated areas, ranging from primary forest to montane grassland to the Highveld, which is a high plateau region of inland South Africa. It is often the first small animal to appear after a burn.
Range elevation: 0 to 1,740 m.
Habitat Regions: terrestrial
Terrestrial Biomes: savanna or grassland ; forest
This African forest shrew has a lifespan ranging from 12-16 months in the wild.
Range lifespan
Status: wild: 12 to 16 hours.
Typical lifespan
Status: wild: 12 to 16 months.
Myosorex varius ranges from dark grey to a brown. Venter hair tends to be grey with white tips and its feet are an off-white color. Its tail is dark-brown dorsally and pale underneath. Total body length averages 12.6 cm, with an average tail length of 4.3 cm, which is about 46% of its entire body length. Mysorex varius is sexually dimorphic in the KwaZulu-Natal/Drankensberg region, with males being significantly larger than females in regards to total mass as well as head and body size; however, populations in other regions, such as Eastern Cape, exhibit little to no sexual dimorphism. Body-size is correlated to habitat altitude, as higher altitude individuals tend to be much smaller than those resident to lower altitudes. Myosorex varius is endothermic and bilaterally symmetric. It has a basal metabolic rate of 38.9 J/g hr. The forest shrew’s body temperature is highly variable, ranging from 33.2 to 38.3 degrees C. It can withstand temperatures as low as 6 degrees C by increasing heat production.
Average mass: 12 g.
Average length: 12.6 cm.
Sexual Dimorphism: sexes alike; male larger
Other Physical Features: endothermic ; bilateral symmetry
The main predator of forest shrews is barn owls. However, water mongooses, striped weasels and striped polecats are also significant predators as well. To avoid predation, they only leave their nest to obtain food and to defecate. When they do leave their nest, it only leaves for small amounts of time to avoid contact with predators. When in danger, they let out a sharp squeak to alert their nest mate of the potential threat.
Known Predators:
The mating system of Myosorex varius has not been documented. Single breeding pairs are often found in nests. Many species of shrew (e.g., least shrews) are promiscuous. Myosorex varius has never been successfully bred in captivity.
Myosorex varius breeds seasonally from September to March, which correlates to the wet seasons of spring and summer. Although it is known to be a seasonal breeder, pregnant females are found year round, with the exception of December. At higher altitudes, breeding season may be delayed for a month due to lower ambient temperatures. Males court female by chasing and grabbing potential mates by the loose skin surrounding the neck. Litters range in size from 2 to 5 pups, with an average of 3. Neonates weigh about 1g at birth. For the first 5 days after parturition, offspring nipple cling. Then, they begin caravanning, which initially consists of the offspring grabbing the mother’s fur with their teeth in a cluster. At about 10 to 13 days old, young form a chain by grabbing ahold of one another, while the lead pup grabs ahold of the mother. Weaning is complete by 20 to 25 days after birth. Females exhibit post-partum estrus and often comes into heat within hours after giving birth.
Breeding season: Myosorex varius breeds during the wet season of spring and summer.
Range number of offspring: 2 to 5.
Average number of offspring: 3.
Range weaning age: 20 to 25 days.
Average weaning age: 24 days.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous ; post-partum estrous
Prior to weaning, Myosorex varius females provide food and protection for their offspring. Once pups are fully weaned, they become independent of their mother's care.
Parental Investment: female parental care ; pre-weaning/fledging (Provisioning: Female, Protecting: Female); pre-independence (Provisioning: Female, Protecting: Female)
The forest shrew (Myosorex varius) is a species of shrew in the mouse shrew family, Soricidae.[2] It is found in Lesotho, South Africa, and Eswatini.[1] Its natural habitats include temperate forests, dry savanna, Mediterranean-type shrubby vegetation, and temperate grassland.[1] The term "forest shrews" in the plural is sometimes confusingly used to collectively refer to a different genus, Sylvisorex.
The forest shrew grows to a length around 12.5 cm (5 in) with a tail of 4.3 cm (1.7 in) and an average mass of about 12 g (0.4 oz). In KwaZulu-Natal and the Drakensberg region, the males are larger than the females, but in the Cape Colony, the sexes are of similar sizes. This shrew is covered in short, dense fur, dark grey or brown above and paler underneath.[3]
The forest shrew is native to South Africa, Lesotho, and Eswatini. In upland areas, it is often the commonest small mammal, but it is less common in coastal areas. It is found in a wide range of primary and secondary habitats, including forests, grassland, scrub, semidesert, karoo, and fynbos.[1]
The forest shrew excavates a shallow burrow or takes over the burrow of another small mammal. The complex of passages has several entrances and a nesting chamber containing dry grasses. These shrews are territorial and a breeding pair of shrews is often found in a nest.[3]
The forest shrew is mainly nocturnal and is an insectivore, but its diet also includes any small invertebrates it can find, including earthworms, millipedes, centipedes, crustaceans, and spiders. The forest shrew is preyed upon by barn owls, marsh mongooses, striped weasels, and striped polecats. To avoid predation, it spends most of its time in its burrow and only leaves when it needs to feed or defecate. Its droppings are very pungent.[3]
The breeding season varies across the forest shrew's range. In some areas, breeding takes place all year round, but in others, it is correlated with the higher rainfall which occurs in the summer, while unusually wet weather at other times of year can spark further reproductive activity.[4]
The forest shrew often contains the brachylaimid trematode Renylaima capensis in its kidney and ureter. This parasitic fluke has been found to have a three-host lifecycle, the first intermediate host being the terrestrial slug Ariostralis nebulosa and the second, another slug Ariopelta capensis. The forest shrew feeds on both these slugs.[5]
Feeding as it does on small invertebrates, the forest shrew tends to accumulate any environmental contaminants in its tissues. Earthworms are known to bioaccumulate lead and the levels of lead in forest shrews are found to rise when they eat contaminated earthworms. This enables the shrews to be used as bioindicators of heavy metal pollution.[6]
The IUCN lists the forest shrew as being of "Least Concern" because it has a wide distribution and is common over much of its range and the population seems stable. It is able to adapt to variations in its habitat and no specific threats have been identified.[1]
{{cite book}}: |first1= has generic name (help) The forest shrew (Myosorex varius) is a species of shrew in the mouse shrew family, Soricidae. It is found in Lesotho, South Africa, and Eswatini. Its natural habitats include temperate forests, dry savanna, Mediterranean-type shrubby vegetation, and temperate grassland. The term "forest shrews" in the plural is sometimes confusingly used to collectively refer to a different genus, Sylvisorex.
