The maned rat or (African) crested rat (''Lophiomys imhausi'') is a nocturnal, long-haired and bushy-tailed East

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

rodent Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are n ...

that superficially resembles a porcupine. The world's only poisonous rodent, the maned rat borrows toxins from plants to fend off predators.

Description

The maned rat's body can grow up to long, or from head to tail. The coat consists of long, silver and black-tipped guard hairs over a dense, woolly, grey and white undercoat, with the face and limbs having short, black fur. A mane of longer, coarser black-and-white banded hairs extends from the top of the animal's head to just beyond the base of the

tail The tail is the section at the rear end of certain kinds of animals’ bodies; in general, the term refers to a distinct, flexible appendage to the torso. It is the part of the body that corresponds roughly to the sacrum and coccyx in mammal ...

. This mane is bordered by a broad, white-bordered strip of hairs covering an area of glandular skin. The forelimbs and hind limbs have short black fur. The forefeet are large and digit 1 of the forefeet does not have a claw while digits 2-5 have a well developed claw. When the animal is threatened or excited, the mane erects and this strip parts, exposing the glandular area. The hairs in this area are, at the tips, like ordinary hair, but are otherwise spongy, fibrous, and absorbent with a honeycomb structure. The rat is known to deliberately smear these hairs with poison from the bark of the '' Acokanthera schimperi'', the poison arrow tree, on which it chews, thus creating a defense mechanism that can sicken or even kill predators which attempt to bite it. It is the only mammal known to utilize and store toxins from a different species in nature to protect itself, with no known adverse effects to themselves. ''L. imhausi'' differs from typical Muridae in having the

temporal fossa The temporal fossa is a fossa (shallow depression) on the side of the skull bounded by the temporal lines and terminating below the level of the zygomatic arch. Boundaries * Medial: frontal bone, parietal bone, temporal bone, and sphenoid bon ...

roofed over a thin plate of bone, rudimentary clavicles, and an opposable hallux. The dorsal surface of the skull is covered with small bony projections which gives it a pebbled look. The projections are 0.3mm across and are separated every 0.3mm. On these grounds, it has been made the type of a family; its dentition, however, is typical Cricetine. The dental formula is 1/1, 0/0, 0/0, 3/3, giving it a total of 16 teeth. The cusps of the molars are arranged biserially and connected medially by longitudinal enamel crests.

Diet

Its diet in the wild consists largely of leaves,

fruit In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering. Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in particu ...

, and other plant material, but it has been known to eat meat, cereals, root vegetables, and

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three ...

s in captivity. Food is eaten by sitting on its haunches and using its forepaws to bring food items to its mouth. It is the only species in the super family

Muroidea The Muroidea are a large superfamily of rodents, including mice, rats, voles, hamsters, lemmings, gerbils, and many other relatives. Although the Muroidea originated in Eurasia, they occupy a vast variety of habitats on every continent excep ...

whose stomach is highly compartmentalized. The stomach contains five anatomically discrete sections that superficially resemble the sacculated configuration characteristic of

ruminant Ruminants (suborder Ruminantia) are hoofed herbivorous grazing or browsing mammals that are able to acquire nutrients from plant-based food by fermenting it in a specialized stomach prior to digestion, principally through microbial actions. The ...

artiodactyls The even-toed ungulates (Artiodactyla , ) are ungulates—hoofed animals—which bear weight equally on two (an even number) of their five toes: the third and fourth. The other three toes are either present, absent, vestigial, or pointing poster ...

. By virtue of its large size and biomass, ''L. imhausi'' may be one of the few muroid rodents that can harbor a symbiotic microflora in the foregut and profit metabolically from gastric fermentation of cellulose.

Habitat

The

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

of the maned rat

ranges In the Hebrew Bible and in the Old Testament, the word ranges has two very different meanings. Leviticus In Leviticus 11:35, ranges probably means a cooking furnace for two or more pots, as the Hebrew word here is in the dual number; or perhaps ...

from nearly sea level, in Ethiopia and Somalia, to more typically the drier, highland forests and woodlands of Somalia, Ethiopia, Sudan, Tanzania, Uganda, and Kenya. Fossil remains have been found as far north as Israel, however. They are often found in rocky areas or in hollow tree trunks and holes along the tops of ravines, and have also been found nesting among rocks on cliff-faces.

Reproduction

The maned rat was believed to be solitary, but is now known to be somewhat sociable, with multiple animals trapped in the same territory; they purr and groom one another. Thus it is possible they form family groups of a male, female, and offspring. The litter size is 1–3. The young are slightly haired at birth and white markings and black stripes on the body are visible after 9 days. By day 13, the eyes open. The hair is sufficiently long that the crest can be erectile by day 20. The newborns become mobile by day 23 and are weaned by day 40.Jonathan Kingdon

''The Kingdon Field Guide to African Mammals''

Citations

General and cited references

*Jansa, S. A. and M. Weksler. 2004. Phylogeny of muroid rodents: relationships within and among major lineages as determined by IRBP gene sequences. Molecular Phylogenetics and Evolution, 31:256-276. *Kingdon, Jonathan. ''East African Mammals''. Chicago: University of Chicago Press, 1974. 519–526. * Jonathan Kingdon, Bernard Agwanda, Margaret Kinnaird, Timothy O'Brien, Christopher Holland, Tom Gheysens, Maxime Boulet-Audet and Fritz Vollrath 2011 ''A poisonous surprise under the coat of the African crested rat'' Proc. R. Soc.

* Jonathan Kingdon,

David Happold David Christopher Dawber Happold, (born 19 April 1936 in Salisbury, Wiltshire, England), in publications often D. C. D. Happold, is a British-Australian mammalogist. His main research interests are the small mammals (bats, shrews, and rodents) of ...

, Thomas Butynski, Michael Hoffmann, Meredith Happold, Jan Kalina, ''Mammals of Africa'', Vol. 1-6 * Jonathan Kingdon,
The Kingdon Field Guide to African Mammals
' * Database entry includes a brief justification of why this species is of least concern

External links

* * Video of animal, hair wicking fluid and SEM image of hair on YouTube: https://www.youtube.com/watch?v=pLheG3aSpVU {{Taxonbar, from=Q852793 Mammals described in 1867 Muridae Rodents of Africa