Natives of the Congo region, the Mangbetu, believe that the hero shrew possesses magical powers. This shrew is believed to invoke powers of bravery and immunity from wounds. Parts of the hero shrews are worn as tailismans bestowing invincibility in war. Naturalist Herbert Lang and James Chapin wrote:
"The Mangbetu gave it a name meaning 'hero shrew'. Those engaging in warfare or setting out upon an equally dangerous enterprise such as hunting elephants are anxious to carry along even a fraction of the ashes of this shrew. Though only worn somewhere about their body, they believe that neither spears nor arrows, nor any kind of an attack can seriously injure them, much less bear them down....Whenever they have a chance they take great delight in showing to the easily fascinated crowd its extraordinary resistance to weight and pressure. After the usual hubbub of various invocations, a full-grown man weighing some 160 pounds steps barefoot on the shrew. Steadily trying to balance himself upon one leg, he continues to vociferate several minutes. The poor creature seems certainly to be doomed. But as soon as his tormentors jump off, the shrew after a few shivering movements escapes and is none the worse for this mad experience and apparently in no need of the wild applause and exhortations of the throng (Allen, 1917)."
Perception Channels: tactile ; chemical
Researchers have found the hero shrew in Africa but the population has not been evaluated.
IUCN Red List of Threatened Species: least concern
None
The hero shrew is important locally. The tribe's people believe that any part of the hero shrew will act as a tailsman to save them from peril.
A report by Kingdon suggests that hero shrews prefer an environment that is dense in undergrowth of wild ginger and arrowroot. Although this would suggest that the hero shrew is an herbivore, it is not. In the field, Land recorded a variety of food items in the stomachs of trapped Scutisorex somereni including insects, caterpillars, earthworms, and the remain of frogs. In captivity hero shrews also consume mammal meat if given the opportunity.
The range of Scutisorex somereni, the hero shrew, is restricted to the forest belt in Africa. The countries located within the forest belt range from southwestern Uganda, eatern Zaire, and to northern Rwanda.
Biogeographic Regions: ethiopian (Native )
Swamps and waterlogged areas are common in the parts of Africa occupied by this species and have specialized flora and fauna (Kingdon, 1971). Hero shrews prefer areas of trees, palms, and dense undergrowth at low elevation.
Terrestrial Biomes: rainforest
"The hero shrew is a large gray shrew with a thick woolly fur (Kingdon 85)." The head and body lengths range from 120 to 150 mm, and the tail length can vary from 68 to 95 mm. The weight is also variable between 30 to 115 g. The pelage is long, thick and coarse. According to Ducommun the hairs of shrews in general function as complex protective structures. The pelage of the hero shrew consists of sensitive tactile and projectile components. It is hypothesized that the projectile, rigid hairs help to disperse scent (Ducommun et al. 630). "The armored shrew, Scutisorex somereni, is an African giant shrew with long fur. The well-developed shield shows modifications for which no plausible explanation is yet available. This big shrew is well known for other enigmatic structures, namely the vertebrae with lateral and ventral interlocking spines and eleven instead of five lumbar vertebrae, a condition no recorded in any other mammal (Ducommun et al. 638)."
The hero shrew is one of the most modified among the vertebrates (Kingdon 1974). The spine is spectacular and is equipped with extra joints that allow for flexibility. The spine has been described as a large bony buttress, which is key to its unusual strength. The size, shape and articulation of the lumbar region is considerabley altered from other members of the insectivore family. The spine structure reduces compression along the postcranial body. The hero shrew's spinal column has the ability to withstand extreme loading of weight. Each vertebrae between the rib cage and the hips is a corrugated cylinder. The spine has a series of complex interlocking tubercles that articulate with the previous and succeeding vertebrae. The series of tubercles have also been called the scaling morphology. This scaling morphology reduces the compression along the postcranial body allowing the hero shrew to withstand the weight of a 160 pound man. Currently there is not a satisfactory ecological, behavioral, or morphological explanation for such a super structured spine.
Although the spine is robust, the rest of the postcranial vertebral column is not especially fortified. The morphology of the axial skeletion is approppriate for handling large loads, but the appendicular skeleton is not (Cullinane el al. 449). The difference between the shrew's strong spine and the rest of its limbs is striking. The limbs, according to Cullinane et al, do not exhibit a significant difference in robustness when compared to other small mammals.
The mass of the spine accounts for nearly 4 percent of the hero shrew's body weight. Comparing the spinal column mass to body mass ratio of other small mammals, we find that for small mammals the spinal column to body ratio ranges only between .5 and 1.6 percent. This is a significant difference that is not understood fully. The unusual spinal morphology was not recognized as an anomaly at first because early investigation of the hero shrew consisted solely of reviewing just the skull and the skin characteristics. Not until 1917 when a researcher named Allen found a preserved specimen, at the American Museum, did the spine begin to be investigated.
Range mass: 30 to 115 g.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: sexes alike
There is little information on the reproduction of the hero shrew. Ther breeding behavior has not been observed. The only mention of reproduction is an account that two lactating females were caught in May and three sexually inactive animals were caught in the same month (Kingdon 91).
Key Reproductive Features: gonochoric/gonochoristic/dioecious (sexes separate); sexual
The hero shrew (Scutisorex somereni), also known as the armored shrew,[3] is a large shrew native to the Congo Basin of Africa. Its features are typical of a white-toothed shrew − short legs, slender snout, dense fur − except for a highly unusual spinal column. It has corrugated interlocking vertebrae that are unique among mammals except for its sister species, Thor's hero shrew. This unique adaptation allows the animal to bear a huge amount of weight on its back − 72 kg (159 lb) according to an expedition team.
The hero shrew lives in both lowland and mountain forests. They live in the undergrowth, feeding primarily on invertebrates. The evolutionary benefit of its unusual spine is not known; it is hypothesized that it allows the animal to push itself under logs and between palm leaves and the tree's trunk to find food. Local tribes of people believe the hero shrew holds magical powers. It is classified as Least Concern by IUCN.
Externally, the hero shrew resembles a typical large shrew. It has short legs, a slender snout, and small eyes. It has dense, coarse fur that is gray in color. It has two types of fur; some hair strands provide sensory functions while other produce scent. The hero shrew aggressively marks its territory, contorting its body to mark objects with its scent. It is thought that the odor repels other members of its species. The chemical it emits can discolor its fur yellow.[4]
The hero shrew lives in the forest undergrowth in sparsely populated areas, which leads to it rarely being seen by humans. It is primarily an insectivore, but will eat small amphibians and lizards in the wild, and bird and mammal meat in captivity. A fully grown hero shrew's body is 12–15 centimetres (4.7–5.9 in) in length with a tail of 6.8–9.5 centimetres (2.7–3.7 in).[4] It weighs 70–113 grams (2.5–4.0 oz).[5] It does not exhibit sexual dimorphism. The breeding habits of the hero shrew have not been observed.[6]
The vertebrae of the hero shrew are thick, corrugated cylinders.[5] The vertebrae interlock on their sides and lower surfaces. The animal's spine has bony projections that mesh to form a strong yet flexible backbone.[4] The differences are especially pronounced in the lower back between the rib cage and hips.[5] The hero shrew has 11 lumbar vertebrae, in contrast to a typical mammal which has 5 such vertebrae. The spine of the hero shrew accounts for 4% of its body weight, in contrast to 0.5–1.6% for a typical small mammal.[4] The ribs of the shrew are thicker than those of similarly sized mammals and the spinal muscles are significantly different. Its abdominal muscles are reduced, while its spinal muscles are enlarged. As a result, the hero shrew has a peculiar gait with its spine flexing in a snake-like manner.[4]
During an expedition to the Congo region in the 1910s, the natives demonstrated the remarkable strength of the hero shrew to naturalists Herbert Lang and James Chapin. After some mystical preparation, an adult male estimated to weigh 72 kg (159 lb) stepped on a shrew and balanced himself on one foot. After several minutes, the man stepped off and the shrew left unharmed.[7] The combination of animal's vertebral strength and its convex curvature behind the shoulder kept its vital organs from being crushed in the demonstration.[8] The feat represented a weight of roughly 1000 times the animal's body weight, the equivalent of a human holding 10 elephants.[9] Relative to body size, the hero shrew's spine is roughly four times more robust than any other vertebrate (excluding its sister species).[8]
Despite its great strength, the hero shrew's spine is easily flexed sagittally (the muscles for doing this are well developed).[9] As a result, the animal can turn 180° within a burrow only slightly wider than the shrew.[4] However, the animal cannot extend its spine or bend it laterally.[9] Its intervertebral joints are five times more resistant to twisting along the axis than a common rat, adjusted for size.[8]
The hero shrew is found in tropical rainforest in the Congo Basin and nearby mountains, over an altitudinal range of 700 to 2230 m. It appears to be dependent on forest habitat. In the mountains it is often present near streams. Its range includes Burundi, the Democratic Republic of the Congo, Rwanda, and Uganda, but apparently does not extend west of the Oubangi River.[1]
The hero shrew is listed as a Least Concern species by the International Union for Conservation of Nature (IUCN). It is thought to have a large population and relatively wide distribution. Its distribution overlaps multiple protected areas and thus the hero shrew is unlikely to experience significant population decline in the near future.[1]
Typically, the backbone is thought to be one of the most conserved parts of the skeleton. Why the hero shrew did not follow this pattern has presented a significant puzzle.[4] Prior to 2013, there was no satisfactory explanation for adaptive advantage of the strong spine.[5][10] In 1974, Jonathan Kingdon suggested that the robust spine and associated posture keeps the animal's body clear of wet ground in swampy habitats.[8] An alternate idea was that the intricate spine somehow evolved as the consequence of some unrelated adaptive factor, as in the spandrels of St. Marco hypothesis. Neither idea had strong scientific support.[9] In 1998, Dennis Cullinane and his colleagues undertook an extensive survey of hero shrew's anatomy and concluded there was no obvious functional significance for the adaptation.[8]
In 2013, a team headed by William T. Stanley of the Field Museum proposed that Scutisorex may use their exceptional spines to lever logs or dead palm leaves, enabling access to invertebrate prey such as earthworms (Oligochaeta) (An interview with William Stanley: on YouTube). Although this behavior has not been directly observed, when local people are collecting beetle larvae in a similar fashion, they often encounter the shrews.[9] Scientist Kristofer Helgen called the new theory "the first compelling explanation for the adaptive significance of the unusual spine."[10]
The hero shrew was first described in 1910 by Oldfield Thomas from a single specimen found in Uganda.[7] But its unique spinal structure was not discovered until 1917, when J. A. Allen examined a preserved specimen from the American Museum of Natural History.[6] The name "hero shrew" stems from the local Mangbetu name for the animal.[6]
The hero shrew is revered in its homeland. Its extraordinary strength has led to the shrew being used as a talisman by the local Mangbetu people.[9] Tradition holds that any part of the shrew, even its ashes, will provide invincibility in battle.[4] Local medicine men use the shrew to create a medicine said to provide courage and protection from injury during battle.[8]
The hero shrew (Scutisorex somereni), also known as the armored shrew, is a large shrew native to the Congo Basin of Africa. Its features are typical of a white-toothed shrew − short legs, slender snout, dense fur − except for a highly unusual spinal column. It has corrugated interlocking vertebrae that are unique among mammals except for its sister species, Thor's hero shrew. This unique adaptation allows the animal to bear a huge amount of weight on its back − 72 kg (159 lb) according to an expedition team.
The hero shrew lives in both lowland and mountain forests. They live in the undergrowth, feeding primarily on invertebrates. The evolutionary benefit of its unusual spine is not known; it is hypothesized that it allows the animal to push itself under logs and between palm leaves and the tree's trunk to find food. Local tribes of people believe the hero shrew holds magical powers. It is classified as Least Concern by IUCN.
