The southern short-tailed shrew is the smallest shrew in its genus, measuring 7 to 10 cm (2.8 to 3.9 in) in total length, and weighing less than 14 g (0.49 oz). It has a comparatively heavy body, with short limbs and a thick neck, a long, pointed snout and ears that are nearly concealed by its soft, dense fur. As its name indicates, the hairy tail is relatively short, measuring 1.2 to 2.5 cm (0.47 to 0.98 in). The feet are adapted for digging, with five toes ending in sharp, curved claws. The fur is slate gray, being paler on the underparts.
The southern short-tailed shrew is found in the southeastern United States, from southern Virginia to eastern Texas, and in the Mississippi valley as far as southern Illinois. Within this region, it is found primarily in pine forests. However, these range from dry to wet and even swampy habitats, as well as disturbed forests and abandoned agricultural land.
There are two recognised subspecies:
The southern short-tailed shrew's diet consists of insects, annelids, hypogeous fungi, slugs and snails, centipedes, and spiders. Known predators include snakes, hawks, owls, and foxes. It has been known to store snails for the winter. The saliva is venomous and is injected into the wounds of its prey by the teeth. Its venom is strong enough to kill mice, but is not lethal to humans, though it causes severe pain.
The southern short-tailed shrew is a social animal; it has been known to share its burrow systems with several individuals. The male and female live together during the prebreeding season. The burrows are built in two layers, one near the surface, and a deeper one joined below it. The burrows are often built below logs, which can be penetrated and honeycombed if the log is rotten.
The breeding season lasts from March to November, and females have two or three litters per year. The gestation period lasts from 21 to 30 days, and each litter consists of two to six young. The young are reared in nests of grasses and leaves at the end of a tunnel reaching about 30 cm (12 in) below the ground, or in rotten logs. These nests for the young are much larger than the adults' resting nests.
Blarina carolinensis inhabits the southeastern corner of the United States (Wilson and Ruff 1999). Populations can be found as far north as southern Illinois and south-central Virginia, and as far south as central Florida (Whitaker and Hamilton 1998).
Biogeographic Regions: nearctic (Native )
Blarina carolinensis is the smallest species in the genus. Total length ranges from 75 to 105 millimeters. The tail length ranges from 17 to 30 millimeters. The range in weight is 15 to 30 grams (Nowak 1999). The dorsal pelage is slate colored while the ventral pelage is a paler shade of grey. They have small eyes, a long, highly moveable nose, and small ears (Wilson and Ruff 1999).
Species of Blarina exhibit little geographic overlap, so are usually distinguished from one another by where they occur. Blarina species differ in their number of chromosomes as well. Blarina carolinensis has 36-46 chromosomes, while Blarina brevicauda, found in northeastern North America, has 48 to 50 chromosomes, and Blarina hylophaga, found in the central United States, has 52 chromosomes (Wilson and Ruff 1999).
Range mass: 15 to 30 g.
Range length: 75 to 105 mm.
Other Physical Features: endothermic ; bilateral symmetry
This species of shrew is most commonly found in moist, well-drained habitats containing woody vegetation (Wilson and Ruff 1999). The well-drained soil allows Blarina carolinensis to burrow underground and construct nests.
The nest (located either underground or beneath decomposing logs or stumps) is composed of shredded grass, roots, dry leaves, and other vegetable material (Wilson and Ruff 1999).
Habitat Regions: temperate ; terrestrial
Terrestrial Biomes: forest
Southern short-tailed shrews are primarily carnivorous, though some vegetable matter may be taken (Nowak 1999). Their diet is composed mainly of soil invertebrates. They feed throughout the day but are most active at night and in the early morning and early evening hours (Nowak 1999). Earthworms, centipedes, and berries are examples of this shrew's diet (Davis and Schmidly 1997).
Primary Diet: carnivore (Insectivore , Eats non-insect arthropods)
Southern short-tailed shrews are probably one of the most numerous mammalian members of their communities. They represent an important prey base for their predators and influence the composition of invertebrate communities through their own predation.
Blarina carolinensis has a diverse group of predators. The most common are hawks and owls, especially barn owls (Tyto alba). Coyote, red fox, and large snakes are also known to prey on southern short-tailed shrews (Wilson and Ruff 1999).
Perception Channels: tactile ; chemical
George et. al (1986) recorded the lifespan of most wild individuals to be no longer than a year. Individuals in captivity have been recorded as living up to 33 months.
Status: captivity: 33 (high) months.
Status: wild: 1 (high) years.
Little is known of mating behavior in southern short-tailed shrews.
Southern short-tailed shrews breed twice a year (Wilson and Ruff 1999). The first period of reproduction is between the months of March and June. A peak in breeding activity is reached during this period in April. The second period is between September and November, with a peak in activity reached during October. Gestation ranges between 21 and 30 days. Litter size is 2 to 6 individuals. Once born, the young weigh about one gram. Females reach sexual maturity at about six weeks of life, while males become sexually mature at around twelve weeks of age (Banfield 1974).
Breeding season: March to June and September to November.
Range number of offspring: 2 to 6.
Range gestation period: 21 to 30 days.
Range weaning age: 18 to 21 days.
Range age at sexual or reproductive maturity (female): 6 to 12 weeks.
Range age at sexual or reproductive maturity (male): 6 to 12 weeks.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (Internal ); viviparous
Young are born naked and unable to see (Davis and Schmidly 1997). They are cared for and nursed by their mother in her nest. After 18-20 days of life the young begin to venture from the nest and are weaned shortly after that (Nowak 1999).
Parental Investment: altricial ; female parental care
Southern short-tailed shrews are abundant in suitable habitats throughout their range.
US Federal List: no special status
CITES: no special status
IUCN Red List of Threatened Species: least concern
Southern short-tailed shrews, like their northern cousins, Blarina brevicauda, may have toxins in their saliva (see Comments below). Bites may result in a painful burning sensation that can last some time.
Negative Impacts: injures humans (bites or stings)
Southern short-tailed shrews are helpful to humans by controlling insect populations (Whitaker Jr and Hamilton Jr 1998).
Blarina carolinensis may produce poison in the submaxillary glands, as does its close relative Blarina brevicauda (Davis and Schmidly 1997). This venom is secreted into the saliva and can be injected into prey through a bite wound. However, B. carolinensis does not seem to prey on vertebrates whereas B. brevicauda does frequently, making it less likely to require the use of venom to subdue prey. The test for venom presence in B. carolinensis has not yet been performed.