Shrews II: White-Toothed Shrews (Crocidurinae)
Shrews II
White-toothed shrews (Crocidurinae)
Class Mammalia
Order Insectivora
Family Soricidae
Subfamily Crocidurinae
Thumbnail description
Small mouse-like mammals with long pointed snouts, white teeth, short legs, and small eyes
Size
1.3–5.3 in (3.5–13.5 cm); 0.06–1.5 oz (2–40 g)
Number of genera, species
11 genera; 212 species
Habitat
Typically in moist habitats that are rich in invertebrate prey; can also be found in habitats ranging from arid regions to tropical forests
Conservation status
Critically Endangered: 16 species; Endangered: 16 species; Vulnerable: 36 species; Lower Risk/Near Threatened: 7 species; Data Deficient 6 species
Distribution
Throughout the Old World, found in many African countries, much of continental Europe and southeastern Asia
Evolution and systematics
Among the most ancient of all living animals, shrews have remained almost unchanged over the past 45 million years. This ancient family diverged from other insectivores before the Eocene period, with modern genera (subfamilies Crocidurinae and Soricinae) first appearing in the Miocene in Europe. Soricids later migrated to Africa and North America. The taxonomic status of modern shrews (Soricidae) is currently undergoing a significant overhaul due to considerable recent taxonomic research on the genetics, morphology, ecology, and behavior of shrews. At present, the shrew family is divided into two living subfamilies, the Crocidurinae and the Soricinae. The members of the subfamily Crocidurinae, white-toothed shrews, are further subdivided into 11 genera (Crocidura, Diplomesodon, Feroculus, Myosorex, Paracrocidura, Ruwenzorisorex, Scutisorex, Solisorex, Suncus, Surdisorex, and Sylvisorex). Current generic boundaries are based on very few characters. The delimitation of some genera of the subfamily Crocidurinae is still the focus of considerable genetic and morphologic research.
The genetic distances between different genera of Crocidinurae based on allozyme variation generally support a sub-division of the living species into these genera. Those species of Crocidurinae that have been studied to date show considerable chromosomal and genetic differentiation. Karyotypic and protein electrophoresis studies have been very helpful in identifying many sibling and cryptic species that were difficult to recognize by conventional methods.
Crocidurinae includes the genus Crocidura, which has 151 species—the largest number of living species of any placental mammal genus.
Physical characteristics
Shrews are the smallest of the insectivores. All shrews have short legs, five claws on each foot, short dense fur, small external ears, an elongated, pointed snout with long tactile hairs (vibrissae), and most have relatively long tails. All have extremely small eyes (often hidden in the fur) and relatively poor eyesight, but the sense of smell is keen, as suggested by their long, mobile snouts. The external ears are reduced in some species and usually hidden in their fur. Hearing is acute. The fur is short, dense, and usually some shade of brown or gray. The skull is long and narrow and has no zygomatic arch. The shrew has one of the most primitive brains of all placental mammals; the brain is small and smooth, dominated by large olfactory bulbs. The dentition is unlike any other family. The very large upper and lower incisors slant forward and meet like forceps. The external genitals of some species are enclosed in a fold of skin. Some species have a venomous saliva. Shrews have skin glands and genital or marking glands that secrete a substance with an unpleasant musky odor. The foot is not specialized, except in some aquatic species.
Members of the white-toothed shrew (Crocidurinae) subfamily are initially distinguished from their red-toothed (Soricinae) counterparts by the color of the enamel of the tips of their incisors. Red-toothed shrews have red teeth due to red pigmentations, and white-toothed shrews lack pigmentation. The two exceptions are Chimarrogale and Nectogale, two white-toothed aquatic species placed in the red-toothed subfamily.
Crocidurinae are also characterized by the retention of primitive dental characteristics. Modern forms differ from those of the later Miocene and from one another by the loss of one, two, or three upper and lower antemolars; reduction in the talonid of the lower third molar and greater emargination of the posterior basal outline of the upper premolar and upper first molar. The first set of teeth is shed in the embryonic stage, so that the teeth at birth are the permanent set. Crocidurinines have 26–32 teeth, normally six on each side of the lower jaw.
Differences in physiology, brain anatomy, and morphology are also diagnostic for this subfamily, including the articulation of the mandibular condyle and the position of the mental foramen. The two bones of the lower leg are fused. The cerebrum is less highly developed in the white-toothed shrews than the red-toothed shrews.
There is considerable anatomical variation among genera of Crocidurinae. Suncus etruscus of southern Europe has a body mass of approximately 0.07 oz (2 g), making it one of the smallest mammals known. One of the largest true shrew representatives of the subfamily Crocidurinae is Suncus murinus, with a head and body length of 6 in (15 cm) and weight of 1.0 oz (30 g) for males and 0.7 oz (20 g) for females.
Myosorex is considered the most ancient of the living genera because it has the largest number of teeth. Suncus differ from Crocidura by retention of a fourth upper antemolar. Sylvisorex differ from both Suncus and Crocidura by a lack of tail bristles, and differ even more from Crocidura by the retention of a fourth upper antemolar. In most genera, the genital and urinary systems have a common opening though the skin. Myosorex has an independent urinary tract system.
There are also significant differences in brain development between genera within the Crocidurinae subfamily. Members of Crocidura show more brain development than members of the thick-tailed shrews of the genus Suncus.
Distribution
The subfamily Crocidurinae is Paleotropical in origin; the white-toothed shrews originated in the Old World tropics and radiated across Africa, Europe, and Asia. This is reflected in the pattern of present day Crocidurinae distribution. Some species of Crocidurinae live in arid regions and semideserts.
Habitat
Crocidurinae shrews usually inhabit damp and dry forests, grassland, cultivated areas, and occasionally human settlements and buildings. Some white-toothed shrews in the
Diplomesodon and Crocidura genera live in arid areas and semi-deserts. They are mainly terrestrial, but some take to water freely, and others burrow a little. They are usually abundant wherever there is sufficient ground vegetation to provide cover. They occur over a great altitudinal range and in many kinds of plant communities. Most species prefer moist habitats, but some species are also found in arid regions.
Behavior
Shrews are extremely active, nervous animals. Some are active day and night, others only at night. When frightened, their heart may beat at a rate of 1,200 times per minute. Shrews have been known to die from loud noises, even thunder. Experiments with oxygen consumption suggest that shrews have a higher metabolic rate than mice of similar size. They are active throughout the year, though some go into torpor.
Some genera of Crocidurinae are notably aggressive and voracious. Shrews have been known to fight to the death. It is widely believed that most of these cases occurred during famine, when shrews may have become cannibalistic. The chirping and buzzing vocalizations sometimes heard are thought to be aggressive signals, and shrews may emit a squeak when alarmed or threatened.
Most shrews are solitary, except when they pair off during breeding. Members of Suncus and Crocidura can be tolerant of other shrews of the opposite gender during mating. After a period of initial fighting, a pair may live together. Once the pair bond has formed, the parent shrews may share a nest. Pairs from some species, such as Crocidura russula, have been observed building nests together.
Shrews are often territorial and have relatively small home ranges (0.1–0.25 acres [0.04–0.1 ha]) that vary in size with seasons of the year and with the timing of the animal's mating season. Shrews mark their territories with their scent glands. Data on population densities are limited to a few species. The population densities of shrews varies considerably between species. The recorded population density of the lesser whitetailed shrew on Corsica is 1.9–5.3 animals per hectare.
White-toothed shrews can dig their own burrow but often use those of other animals such as woodmice or molerats. They can tunnel through loose humus and leaf mold and often are active under fallen trees and heaps of brushwood or stone.
Feeding ecology and diet
Shrews are primarily insectivorous and carnivorous, but will eat some plant materials such as seeds and nuts. Considering their high energy needs, it is likely that shrews need to adapt their diet according to food availability throughout the year. Their diets may include frogs, toads, and lizards. In captivity, many species will consume all but the skin, tail, and parts of the limbs of a small mammal; the brain is always eaten first. If no other food is available, some species resort to cannibalism.
The common belief that shrews cannot survive without eating every few hours is not a rule. In some Crocidurinae species, animals are able to lower their body temperatures in response to food scarcity. This is an example of food deprivation triggering torpor, a state of reduced activity level. This energy-saving state permits the animal to survive difficult conditions temporarily. For example, Savi's pygmy shrew (Suncus etruscus) loses 10–15% of its body weight by day, then increases food consumption at night to make up the loss. If food is scarce, the shrew may enter torpor.
Some species of shrews have salivary glands that secrete a poisonous substance that usually immobilizes the prey. There are records of shrew bites to humans that caused great pain. There is some question over whether the saliva of Savi's pygmy shrew is poisonous. These diminutive shrews need to bite their prey only once to subdue them.
Reproductive biology
In the tropics, shrews form monogamous pairs and breed throughout the year, while those living in northern temperate zones usually breed from March to November. The known gestation periods are 17–28 days. There are one or several litters a year with 2–10 young in each litter. The young are born naked and blind in a nest of dried grass or leaves placed under a shelter or in a ground cavity. Weaning appears to occur at 2–4 weeks in most forms. Some zoologists estimate the life span in the wild to be 12–18 months, possibly longer. The oldest known Crocidurinae lived approximately four years.
Among Crocidurinae, the young are hairless for the first week and fully haired at 16 days. The auditory canals of Crocidurinae species open between the fifth and ninth days of life and the eyes open between the thirteenth and fifteenth days. Crocidurinae species begin to wean their young after 20–22 days. The young are practically adults and are sexually mature by 2–3 months.
Within the Crocidura, gestation is 27–31 days; litter size varies from one to 10. Larger litter sizes are associated with higher energy demands on the mother. The young weigh about 0.04 oz (1 g) at birth and are weaned at around 20 days. In Crocidura russula, young females can conceive at approximately 30 days of age.
Some Crocidurinae species and at least one Sorex species, display an unusual caravan behavior. The mother initally carries the young infants in her mouth. Starting on the sixth to tenth day, depending on the species, the mother and her young move in a caravan. At the slightest suspicious sound, one of the baby shrews grasps its mother's fur near the base of the tail. A second shrew grabs onto the first, a third onto the second and so on until the whole litter is lined up behind the female who then pulls her train of offspring.
Conservation status
The greatest threat for the Crocidurinae shrews is environmental disturbance and pollution. Loss of forest habitats has a considerable effect on forest-dwelling species.
Data on the conservation status of most Crocidurinae shrew species are limited due to a paucity of population research. The Crocidurinae shrews included in the 2002 IUCN Red List often belong to very rare and endemic species with restricted distribution and low population densities. Some of the threatened species are only known from the locality of their original description. There is an urgent need for considerable research on most shrew species.
Significance to humans
Shrews may be valuable to agricultural communities as a form of natural control of insect pests due to their consumption of large numbers of insects and insect larvae. They also play a significant role in increasing the rate of litter decay.
Shrews are frequently used for neurological research and in other areas of biomedicine and evolutionary biology. They can also serve as useful indicators of environmental contamination such as heavy metals. Shrews feeding on earthworms in areas with heavy metals in the soil can accumulate significant levels of heavy metals in their tissues.
Species accounts
List of Species
Common European white-toothed shrewSavi's pygmy shrew
Forest musk shrew
Piebald shrew
Forest shrew
Armored shrew
Pearson's long-clawed shrew
Schouteden's shrew
Ruwenzori shrew
Kelaart's long-clawed shrew
Common European white-toothed shrew
Crocidura russula
taxonomy
Crocidura russula (Hermann, 1780), Bas Rhin, France.
other common names
French: Musaraigne musette; German: Hausspitzmaus.
physical characteristics
Head and body length 2.4–3.4 in (6.1–8.6 cm); tail 1.2–1.7 in (3.0–4.3 cm); weight 0.2–0.4 oz (6–12 g). Grayish brown to reddish brown with a silverly luster on its back. The flanks and underside are brownish. The tail is brown on the dorsal surface and gray on the underside with long protruding hairs. The ears are visible. It has 28 completely white teeth (including three upper unicuspids). This species is considered to be more advanced than many other Crocidurinae genera.
distribution
Occurs in Morocco, Algeria, Tunisia, southern and western Europe including an Atlantic island off of France, and on the Mediterranean islands of Ibiza, Sardinia, and Pantelleria.
habitat
Lives in or near farmyards, yards, fields, and at the edges of cities. Close to the Mediterranean, these small shrews are found in brushlands, in the underbrush of cork and in olive groves and the overgrowth of vineyards.
behavior
Generally aggressive and voracious. When provoked, they frequently crouch on the ground with head raised and emit a squeak. This species is more tolerant of conspecifics. During the cold of winter, individuals may share nests. With onset of spring, mature females resume their territorial behavior.
feeding ecology and diet
Their diet consists of invertebrates and the bodies of freshly killed animals. In captivity, the species will consume all but the skin, tail, and parts of the limbs of a small mammal; the brain is always eaten first. They also feed on frogs, toads and lizards.
reproductive biology
Gestation lasts 27–30 days. Litter size varies from three to eleven young. At birth, young weigh 0.02–0.03 oz (0.8–0.9 g). The young open their eyes at 13 days. They are hairless for the first week and fully haired at 16 days. After weaning at around 17–22 days, the young are practically adults, ready to become independent. Young females of this species can conceive at approximately 30 days of age. The expected life span for this species is 34–38 months.
Common white-tooth shrew mothers and young have been observed in caravan, a behavior where a young shrew offspring of six days or older grabs onto the back of its mother, and other young shrews from the litter form a line of shrews by latching onto each other. May form monogamous pairs for breeding.
conservation status
Not threatened.
significance to humans
None known.
Savi's pygmy shrew
Suncus etruscus
taxonomy
Suncus etruscus (Savi, 1822), Pisa, Italy.
other common names
English: Pygmy white-toothed shrew; French: Pachyure etrusque, musaraigne etrusque; German: Etruskerspizmaus.
physical characteristics
Head and body length 1.4–2.1 in (3.6–5.3 cm); tail 0.8–1.2 in (2.1–3 cm). One of smallest mammals in the world; smallest in Europe. Grayish brown dorsal side, blackish brown or ash-gray ventral side. Ears clearly visible. Thirty completely white teeth. Individual long hairs on the tail.
distribution
Mediterranean to India and Sri Lanka. Includes southern Europe, northern Africa, Arabian Peninsula and Asia Minor to Iraq, Turkmenistan, Afghanistan, Pakistan, Nepal, Bhutan, Myanmar, Thailand, and Yunnan (China).
habitat
Lives in old vineyards, olive groves, brushwood yards, cultivated land with low rock walls, dumps, rock piles.
behavior
Considered solitary and intolerant of each other. Their repertoire of vocalizations, made up of chirps and buzzes are regarded as aggressive signals. However, in the laboratory, pairs and young of this species have been observed living peacefully together during breeding season.
feeding ecology and diet
Nothing known.
reproductive biology
In laboratory studies the gestation for Suncus etruscus has been recorded as 27.5 days. Litter sizes of 4–6 were observed in Pakistan while smaller litters of 2–5 offspring have been recorded in captivity. Presumably monogamous when breeding.
conservation status
Not threatened.
significance to humans
None known.
Forest musk shrew
Sylvisorex megalura
taxonomy
Sylvisorex megalura (Jentink, 1888), Junk River, Schieffelinsville, Liberia.
other common names
English: Climbing shrew.
physical characteristics
Head and body length 1.8–4 in (4.5–10 cm); tail 1.5–3.5 in (4–9 cm); weight 3–0.42 oz (12 g). Soft, velvety fur usually longer than that of Suncus. Lack long tail hairs. Upperparts are usually slate gray and underparts are slightly paler.
distribution
Tropical forest zone of Africa, from upper Guinea to Ethiopia, and south to Mozambique and Zimbabwe.
habitat
Inhabit deep forests. Individuals have been observed climbing in trees and in grasslands well away from trees.
behavior
Solitary animal that has been found active during the day and at night.
feeding ecology and diet
Nothing is known.
reproductive biology
Nothing is known.
conservation status
Not threatened.
significance to humans
None known.
Piebald shrew
Diplomesodon pulchellum
taxonomy
Diplomesodon pulchellum (Lichtenstein, 1823), eastern bank of Uraal River, Kazakhstan.
other common names
None known.
physical characteristics
Head and body length 3.5–5.0 in (9.0–12.5 cm); tail 3.5–4.5 in (8.9–11.0 cm). The piebald shrew has a striking color pattern; fur is grayish with an elongated patch of white fur at the nape of the neck. Underparts, feet and tail are white. All hairs are gray at the base. It has fringes of long, supple hair on the soles and toes of the forepaws and hind paw. These fringes increase the support surface of the paws of this sand-dwelling species and facilitate its movement on the sand. The ears are comparatively large.
distribution
Inhabits desert environments within Turkmenistan, Uzbekistan, and southern Kazakhstan (between Lake Balkhash and the Volga River).
habitat
Inhabits the sandy soil of semideserts.
behavior
The piebald shrew is active throughout the year, primarily at night, but sometimes during the day. It is able to dig through sand quickly.
feeding ecology and diet
Primarily consumes lizards and insects. Observed killing lizards by biting the head in captivity. The shrew consumed all parts of the lizard, including the skull and skeleton, but left the feet and tail. When eating insects, only the chitin is not consumed.
reproductive biology
Nothing is known, but probably monogamous when breeding.
conservation status
Not threatened.
significance to humans
None known.
Forest shrew
Myosorex varius
taxonomy
Myosorex varius (Smuts, 1832), Cape of Good Hope, South Africa.
other common names
English: Mouse shrew; French: Musaraigne des bois africaine; German: Sudafrikanische Waldspitzmaus.
physical characteristics
Head and body length 2.8–3.8 in (7.2–9.5 cm), tail 1.2–2 in (3.1–5 cm), weight 0.3–0.7 oz (7–19 g). Dorsal side is brown; ventral side, somewhat lighter, tail relatively short; eyes small; ears reduced. Distinguished by its first upper incisor, which is enlarged and has a hook at the end. This tooth also has a cusp projecting ventrally at the base.
distribution
South Africa, from northwest Cape Province to eastern Transvaal; Lesotho and Orange Free State.
habitat
Moist areas, usually in forests, scrub, or other dense vegetation along the banks of open and forested streams.
behavior
Diurnal and nocturnal, active throughout the year. Members of this genus are primarily solitary except during the breeding season. However, males and females have been observed eating and sleeping together after a period of avoiding each other, aggressive squeaks and/or brief fighting.
feeding ecology and diet
Various invertebrates including insects, snails, spiders, centipedes. Small birds and mammals when available.
reproductive biology
Usually monogamous. Litter size is two to five. Weight at birth is 0.03 oz (1 g). Wean young at 20–22 days. Life span averages 12 months.
conservation status
Not threatened.
significance to humans
None known.
Armored shrew
Scutisorex somereni
taxonomy
Scutisorex somereni (Thomas, 1910), Kyetume, Uganda.
other common names
English: Hero shrew; French: Musaraigne cuirassee, musaraigne armee; German: Schildspitzmaus.
physical characteristics
Head and body length 4.8–6in (12–15 cm); tail 2.7–3.8 in (6.8–9.5 cm); weight 1.1–3.2 oz (30–90 g). Long thick gray fur with thin, chamois-colored streaks. Distinguished by a unique spine having almost double the number of vertebrae of other shrews. The vertebrae have lateral interlocking spines in addition to dorsal and ventral spines. This spine structure may provide
considerable strength to the back, without limiting dorsal, ventral and lateral flexibility. Other characteristics include a naked tail, 30 completely white teeth, and four teats.
distribution
Tropical rainforests of the Zaire Basin and adjacent mountains in Uganda, Rwanda, and Burundi.
habitat
Edges of gallery forests; in fallen leaves and in swampy regions.
behavior
The armored shrew is active both night and day.
feeding ecology and diet
Feeds on small mammals when available as well as insects and some plant matter.
reproductive biology
Probably monogamous. Small litters with one to three offspring.
conservation status
Not threatened.
significance to humans
None known.
Pearson's long-clawed shrew
Solisorex pearsoni
taxonomy
Solisorex pearsoni Thomas, 1924, Central Province, Sri Lanka.
other common names
French: Pachyure aux longues griffes; German: Pearsons Langkrallenspitzmaus.
physical characteristics
Head and body length 5–5.4 in (12.5–13.4 cm); tail 2.4–2.6 in (5.9–6.6 cm). The fur is soft, dark gray along the back with a lighter lustrous underside. Its small ears are fully furred and hidden in fur. Teeth are large and heavy and the anterior incisors are well developed. Claws on the forefeet are very long. The slender tail is closely haired and lacks the scattered long hairs. Twenty-eight completely white teeth.
distribution
Restricted to the central highlands of Sri Lanka, from an altitudinal range of 3,609–6,070 ft (1,100–1,850 m).
habitat
This species is reported to inhabit virgin forest though some individuals have been trapped in long grass.
behavior
Nothing is known.
feeding ecology and diet
Feeds on invertebrates and vertebrates.
reproductive biology
Nothing is known.
conservation status
Endangered. S. personi is restricted to a small area of declining habitat that is being altered by human encroachment.
significance to humans
None known.
Schouteden's shrew
Paracrocidura schoutedeni
taxonomy
Paracrocidura schoutedeni Heim de Balsac, 1959, Kasai, Democratic Republic of the Congo.
other common names
French: Musaraigne a dents blanches du Congo, musaraigne a dents blanches de Schouteden; German: Schildspitzmaus.
physical characteristics
Head and body length 2.6–3.8 in (6.5–9.5 cm); tail 1.4–1.7 in (3.4–4.4 cm); weight 0.3–0.7 oz (10–20 g). Short, fine, black fur, small ears covered with fine fur, short limbs, short claws. The tail has short hair with some long hairs. The teeth are completely white. Paracrocidura is identified as a separate genus on the basis of its distinct dental characteristics. It has 28 white teeth, of which three are maxillary unicuspids. An unusual feature is the straightness of the posterior borders of the fourth premolar and first and second molars, and the development of the first premolar. It also has aliform processes at the inner edge of the upper incisors and a bicuspid second lower premolar.
distribution
Occurs in the lowland primary forests in south Cameroon, Gabon, Democratic Republic of the Congo, and in Central Africa Republic.
habitat
Lowland rainforests.
behavior
Nothing is known.
feeding ecology and diet
Nothing is known.
reproductive biology
Litter size is small, one to three young.
conservation status
Not threatened.
significance to humans
None known.
Ruwenzori shrew
Ruwenzorisorex suncoides
taxonomy
Ruwenzorisorex suncoides (Osgood, 1936), Kalongi, Democratic Republic of the Congo.
other common names
None known.
physical characteristics
Head and body length 3.6–3.74 in (9.2–9.5 cm); tail 2.2–2.5 in (5.5–6.2 cm); weight 0.64 oz (18.2 g). Shiny black fur with paler sides and feet. Stocky body and short head. Hind feet are long. The tail is almost naked and has no long hairs. The external ears are small and round. Primarily distinguished by cranial and dental features. The skull is relatively flat and rectangular in profile. The first lower molar is massive.
distribution
Endemic to the Albertine Rift, occurring from the Ruwenzori Mountains (Uganda), eastern Democratic Republic of the Congo, Burundi and Rwanda.
habitat
Damp, mossy mountain forests. All specimens have been found at elevations of 2,625–6,890 ft (800–2,100 m).
behavior
Comparatively social as indicated by the presence of multiple shrews nesting together.
feeding ecology and diet
Nothing known.
reproductive biology
There is some indication that Ruwenzori shrews breed twice a year. Probably monogamous when breeding
conservation status
Vulnerable.
significance to humans
None known.
Kelaart's long-clawed shrew
Feroculus feroculus
taxonomy
Feroculus feroculus (Kelaart, 1850), central mountains, Sri Lanka, at altitude of 6,000 ft (2,000 m). Initially, this species was identified as a water shrew; more recently identified as a separate species (semi-fossorial).
other common names
French: Pachyure aux longues griffes; German: Kelaarts Langkrallenspitzmaus.
physical characteristics
Head and body length 4.2–4.7 in (10.6–11.8 cm); tail 2.2–2.9 in (5.6–7.3 cm); 1.2–1.3 oz (35–37 g). Known from only a few specimens. The back is slate black, underside is lighter, dark tail with a few whitish hairs at the tip and some individual long hairs, and the forefeet are off-white. It has 30 completely white teeth.
distribution
Endemic to central mountains of Sri Lanka.
habitat
Observed among weeds and other dense undergrowth in wet ravines. Primarily along hillsides of the central mountains of Sri Lanka. It appears to be confined to valleys and slopes of the central mountain range of Sri Lanka at elevations between 5,550 and 6,450 ft (1,850–2,150 m).
behavior
Very little is known about the behavior of this species.
feeding ecology and diet
Feeds on invertebrates, vertebrates and plant material.
reproductive biology
Nothing is known.
conservation status
Endangered. Decline of this species may be due to encroachment of humans on its limited habitat.
significance to humans
None known.
Common name / Scientific name / Other common names | Physical characteristics | Habitat and behavior | Distribution | Diet | Conservation status |
Poll's shrew Congosorex polli | Buffy, fawn, or shades of brown, gray, or black. Coat appears speckled due to light hairs interspersed with dark hairs. May have gray feet. Head and body length 2.4–4.3 in (6–11 cm), tail length 0.9–2.6 in (2.4–6.7 cm). | Moist areas, especially forests or scrub and the dense vegetation lining the banks of mountain streams. Generally solitary, except during breeding season. | Known only from type locality in southern Democratic Republic of the Congo (Zaire). | Mainly insects, but may also eat small birds and mammals. | Critically Endangered |
Gray shrew Crocidura attenuata English: Indochinese shrew | Light brownish gray on upperparts, pale gray on underparts. Underside is faintly tinged with brown. Tail is dark above and light below. Backs of feet are thinly covered with short, pale hairs. | Variety of habitats, from seedling rice fields to cut-down forest-farmlands of weeds and grass. Solitary, except during breeding season. | Assam, India; Nepal; Bhutan; Burma; Thailand; Vietnam; Hainan, China; Taiwan; Peninsular Malaysia; Sumatra; Java; Christmas Islands (Indian Ocean); and Batan Islands, Philippines. | Mainly insects, but may also eat small birds and mammals. | Not threatened |
Canary shrew Crocidura canariensis Spanish: Musarana canaria | Uniform chocolate brown. Head and body length 1.6–4.3 in (4–11 cm). Tail is long and covered with long, white and short, bristly hairs. Foreclaws are not enlarged. | Malpais (barren lava fields), as the species has adapted to the hot and dry conditions of the plains. Very shy animals, little known of reproductive cycles. Very low litter sizes. | Canary Islands, Spain. | Mainly insects. | Vulnerable |
Dsinezumi shrew Crocidura dsinezumi | During winter pelage is pale gray to brown, summer, pelage is usually dark brown. Under parts are lighter. Head and body length 2.6–3.1 in (6.5–8 cm), tail length usually less than 70% of head and body length. | Along river banks and in the foothills with dense vegetation. Generally solitary, except during breeding season. | Japan; Quelpart Islands, Korea; and possibly Taiwan. | Insects and spiders. | Not threatened |
Southeast Asian shrew Crocidura fuliginosa | Dark gray to blackish with a dull, silvery gloss. Underparts are lighter, tail is thin with a few, faint, white hairs. Ears are naked and prominent, eyes are small, feet covered with a few, short white hairs. | Various habitats from montane to lowland forest, cultivated areas, and even caves. Solitary, except during breeding season. | Northern India, Myanmar, adjacent China, Malaysian Peninsula and adjacent islands; perhaps also Borneo, Sumatra and Java; exact distribution unknown. | Mainly insects. | Not threatened |
Horsfield's shrew Crocidura horsfieldii | Upperparts are neutral gray with bottom portions of hairs brown. Underside is dark gray. Tail is paler above than beneath. | Intermediate montane from 4,000 to 6,960 ft (1,220–2,120 m) in areas of fairly heavy cover. Solitary, except during breeding season. | Sri Lanka; northern Thailand to Vietnam; Nepal; Mysore and Ladak, India; Yunnan, Fukien, and Hainan Islands, China; Taiwan; and Ryukyu Islands, Japan. | Mainly insects. | Not threatened |
Lesser white-toothed shrew Crocidura suaveolens English: Lesser shrew | Reddish gray above, slightly lighter underside. Ears are short-haired and prominent, tail is covered with fine, long, white hairs. Tail length 0.9–1.7 in (2.4–4.4 cm), head and body length 2–3 in (5–7.5 cm). | Temperate woodlands and steppe. Generally solitary, not highly territorial, breeding season extends from March to September. | Entire Palearctic from Spain to Korea; Atlantic islands (Scilly, Jersey, Sark, Ushant, Yeu); many Mediterranean islands including Corsica, Crete, Cyprus, and Menorca; and Tsushima and Ullong Do between Korea and Japan. | Mainly insects. | Not threatened |
Schaller's mouse shrew Myosorex schalleri | Buffy, fawn, or shades of brown, gray, or black. Underparts of hairs are brown, giving speckled effect. Head and body length 2.4–4.3 in (6–11 cm), tail length 6–2.6 in (2.4–6.7 cm). | Moist areas, especially forests or scrub and the dense vegetati on lining the banks of mountain streams. Generally solitary, except during breeding season. | Eastern Democratic Republic of the Congo (Zaire), Itombwe Mountains, "Nzombe (Mwenga)". | Mainly insects, but will also eat small birds and mammals. | Critically Endangered |
Greater shrew Paracrocidura maxima | Short, large snout, short and visible ears, short limbs and claws. Body covered in thin, short, ashy black or dark brown hair, tail is black. Head and body length 2.6–3.8 in (6.5–9.6 cm), tail length 1.3–1.8 in (3.3–4.6 cm). | Rainforests at elevations of about 660–7,710 ft (200–2,350 m). Terrestrial. | Democratic Republic of the Congo (Zaire), Rwanda, and Uganda. | Mainly insects. | Not threatened |
Common name / Scientific name / Other common names | Physical characteristics | Habitat and behavior | Distribution | Diet | Conservation status |
Grauer's shrew Paracrocidura graueri | Short, large snout, short and visible ears, short limbs and claws. Body covered in thin, short, ashy black or dark brown hair, tail is black. Head and body length 2.6–3.8 in (6.5–9.6 cm), tail length 1.3–1.8 in (3.3–4.6 cm). | Rainforests at elevations of about 660–7,710 ft (200–2,350 m). Terrestrial. | Itombwe Mountains, Democratic Republic of the Congo (Zaire). | Mainly insects. | Critically Endangered |
Aberdare shrew Surdisorex norae | Pelage is deep lustrous brown with pale frosting, under parts are paler and buffier. Tail is dark brown above and below. Fur is long, dense, and coarse. Head and body length 2.3–4.3 in (6–11 cm), tail length 0.9–2.6 in (2.4–6.7 cm). | Moss and heather cloud forests of the Kenyan mountains, at altitudes of 9,190–10,830 ft (2,800–3,300 m). Active both day and night. Stay mainly in burrow systems. | Aberdare Range, Kenya. | Mainly insects, but will also eat small mammals and birds. | Vulnerable |
Mt. Kenya shrew Surdisorex polulus | Pelage is deep lustrous brown with pale frosting, under parts are paler and buffier. Tail is dark brown above and below. Fur is long, dense, and coarse. Head and body length 2.3–4.3 in (6–11 cm), tail length 0.9–2.6 in (2.4–6.7 cm). | Moss and heather cloud forests of the Kenyan mountains, at altitudes of 9,190–10,830 ft (2,800–3,300 m). Active both day and night. Stay mainly in burrow systems. | Mount Kenya, Kenya. | Mainly insects, but will also eat small mammals and birds. | Vulnerable |
Volcano shrew Sylvisorex vulcanorum | Upperparts generally slaty gray, underparts are paler. Fur is soft and velvety. Head and body length 1.8–3.9 in (4.5–10 cm), tail length 1.6–2.6 in (4–6.5 cm). | Deep forest, as well as in grassy areas well away from trees. Arboreal, terrestrial, both diurnal and nocturnal. Solitary. | High altitude rainforest of eastern Democratic Republic of the Congo (Zaire), Uganda, Rwanda, and Burundi | Mostly insects taken through foraging. | Not threatened |
Sunda shrew Crocidura monticola | Body uniform dull gray-brown. Tail paler with sparse, long, pale hair at the base, usually extending over 0.3 in (l cm) along the tail. Head and body length 1.6–7.1 in (4–18 cm), tail length 1.6–4.3 in (4–11 cm). | Damp and dry forests, grassland, cultivated areas, and occasionally human settlements and buildings. Aggressive. Litter size ranges from one to 10 offspring. | Borneo, Java, and Peninsular Malaysia. | Invertebrates and freshly killed animals. | Not threatened |
Negros shrew Crocidura negrina | Small animal with long, slender tail. Pelage is dark, blackish, tinged with gray on upper parts. Underparts are dark brown with white spots. | This species has only been recorded from Cuernos de Negros mountain, Negros Island, the Philippines at an altitude range of 1,640–4,760 ft (500–1,450 m). Aggressive. Litter size ranges from one to 10 offspring. Solitary, except during breeding season. | Primary forest at 1,640–4,760 ft (500–1,450 m) on southern Negros Island, Philippines. | Mainly insects, invertebrates, and freshly killed animals. | Critically Endangered |
Resources
Books
Corbet, G. B., and J. E. Hill. The Mammals of the Indomalayan Region: A Systematic Review. Oxford: Oxford University Press, 1992.
IUCN. Eurasian Insectivores and Tree Shrews—Status Survey and Conservation Action Plan. Gland, Switzerland: IUCN, 1995.
Merritt, J. F., G. L. Kirkland, and R. K. Roberts, eds. Advances in The Biology of Shrews. Pittsburgh: Carnegie Museum of Natural History, Special Publication 18, 1994.
Mitchell-Jones, A. J., et al. The Atlas of European Mammals. London: Poyser Natural History—Academic Press, 1999.
Wilson, D. E., and S. Ruff, eds. The Smithsonian Book of North American Mammals. Washington, DC, and London: Smithsonian Institution Press, 1999.
Wójcik, J. M., and M. Wolsan, eds. Evolution of Shrews. Bialowieza: Mammal Research Institute, Polish Academy of Sciences, 1998.
Organizations
IUCN Species Survival Commission, Insectivore Specialist Group, Dr. Werner Haberl, Chair. Hamburgerstrasse 11, Vienna, A-1050 Austria. Phone: +4315861094. Fax: +4315861094. E-mail: [email protected] Web site: <http://members.vienna.at/shrew/itses.html>
Corliss Karasov