Malagasy Giant Rat
Encyclopedia
The Malagasy Giant Rat also known as the Votsovotsa, is a nesomyid
rodent
found only in the Menabe
region of Madagascar
. It is an endangered species due to habitat loss, slow reproduction, and limited range (20 square kilometres north of Morondava
, between the rivers Tomitsy and Tsiribihina) Pairs are monogamous and females bear only one or two young per year. It is the only extant species in the genus Hypogeomys; another species, Hypogeomys australis
, is known from subfossil
remains a few thousand years old.
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s, though maintaining many rat-like features especially in the face. Males and females both grow to roughly rabbit-size, around 1.2 kg (2.6 lbs) and 33 cm (13 in), though with an additional 20-25 cm (8-10 in) of dark tail. They have a coarse coat which varies from gray to brown to reddish, darkening around the head and fading to white on the belly. They also have prominent, pointed ears and long, muscular back legs, used for jumping to avoid predators. They can leap almost 3 ft (90 cm) in the air, for which reason they are sometimes called Giant Jumping Rats.
. Once mated, a pair will stay together until one of them dies. On the death of a mate, females tend to remain in the burrow until a new male is found. While males usually wait for a new mate as well, they do occasionally move to live with a widowed female. Females give birth to a single offspring after a gestation of 102-138 days (number observed in captivity) once or twice during the mating season, which coincides with the Madagascar rainy season from December to April. The young are raised by both parents, remaining in the family burrow for the first 4-6 weeks, then increasingly exploring and foraging outside. Young males stay with the family unit for one year before achieving sexual maturity and leaving to find their own burrow. Females do not mature for 2 years and remain with their parents for the extra year. Males are extremely protective of their young. They are known to increase their own predation risk to follow or defend their offspring.
. When foraging, the rats move on all fours, searching the forest floor for fallen fruit, nuts, seeds, and leaves. They have also been known to strip bark from trees and dig for roots and invertebrates. Pairs are highly territorial and both members will defend their territory from other rats. They mark their territory with urine
, feces
, and scent gland secretions.
Nesomyidae
Nesomyidae is a family of African rodents in the large and complex superfamily Muroidea. It includes several subfamilies, all of which are native to either continental Africa or to Madagascar...
rodent
Rodent
Rodentia is an order of mammals also known as rodents, characterised by two continuously growing incisors in the upper and lower jaws which must be kept short by gnawing....
found only in the Menabe
Menabe
Menabe is a region in western Madagascar. It is named for the 18th century Sakalava kingdom of Menabe. The capital is Morondava.-History:Menabe is the southern part of the Sakalava territory. Tradition holds that it was founded by Adriamandazoala . Its territory was increased under the legendary...
region of Madagascar
Madagascar
The Republic of Madagascar is an island country located in the Indian Ocean off the southeastern coast of Africa...
. It is an endangered species due to habitat loss, slow reproduction, and limited range (20 square kilometres north of Morondava
Morondava
Morondava is a city located in Menabe Region, of which it is the capital, in Madagascar. It is located in the delta of the Morandava River at .-Communication:...
, between the rivers Tomitsy and Tsiribihina) Pairs are monogamous and females bear only one or two young per year. It is the only extant species in the genus Hypogeomys; another species, Hypogeomys australis
Hypogeomys australis
Hypogeomys australis is an extinct rodent from central and southeastern Madagascar. First described in 1903, it is larger than its close relative, the living Hypogeomys antimena, which occurs further west, but otherwise similar. Average length of the femur is 72.1 mm, compared to 63.8 mm...
, is known from subfossil
Subfossil
Subfossil refers to remains whose fossilization process is not complete, either for lack of time or because the conditions in which they were buried were not optimal for fossilization....
remains a few thousand years old.
Physical description
Malagasy Giant Rats have an appearance somewhat similar to rabbitRabbit
Rabbits are small mammals in the family Leporidae of the order Lagomorpha, found in several parts of the world...
s, though maintaining many rat-like features especially in the face. Males and females both grow to roughly rabbit-size, around 1.2 kg (2.6 lbs) and 33 cm (13 in), though with an additional 20-25 cm (8-10 in) of dark tail. They have a coarse coat which varies from gray to brown to reddish, darkening around the head and fading to white on the belly. They also have prominent, pointed ears and long, muscular back legs, used for jumping to avoid predators. They can leap almost 3 ft (90 cm) in the air, for which reason they are sometimes called Giant Jumping Rats.
Reproduction and maturation
These rats are one of the few rodent species to practice monogamyMonogamy
Monogamy /Gr. μονός+γάμος - one+marriage/ a form of marriage in which an individual has only one spouse at any one time. In current usage monogamy often refers to having one sexual partner irrespective of marriage or reproduction...
. Once mated, a pair will stay together until one of them dies. On the death of a mate, females tend to remain in the burrow until a new male is found. While males usually wait for a new mate as well, they do occasionally move to live with a widowed female. Females give birth to a single offspring after a gestation of 102-138 days (number observed in captivity) once or twice during the mating season, which coincides with the Madagascar rainy season from December to April. The young are raised by both parents, remaining in the family burrow for the first 4-6 weeks, then increasingly exploring and foraging outside. Young males stay with the family unit for one year before achieving sexual maturity and leaving to find their own burrow. Females do not mature for 2 years and remain with their parents for the extra year. Males are extremely protective of their young. They are known to increase their own predation risk to follow or defend their offspring.
Lifestyle and behavior
Completely nocturnal, the Giant Rats live in burrows up to 5 m (16 ft) across with as many as 6 entrances. Entrances, even those in regular use, are kept blocked by dirt and leaves to discourage predation by the Malagasy ground boa. The other main predatory threat is the puma-like fossaFossa (animal)
The fossa is a cat-like, carnivorous mammal that is endemic to Madagascar. It is a member of the Eupleridae, a family of carnivorans closely related to the mongoose family . Its classification has been controversial because its physical traits resemble those of cats, yet other traits suggest a...
. When foraging, the rats move on all fours, searching the forest floor for fallen fruit, nuts, seeds, and leaves. They have also been known to strip bark from trees and dig for roots and invertebrates. Pairs are highly territorial and both members will defend their territory from other rats. They mark their territory with urine
Urine
Urine is a typically sterile liquid by-product of the body that is secreted by the kidneys through a process called urination and excreted through the urethra. Cellular metabolism generates numerous by-products, many rich in nitrogen, that require elimination from the bloodstream...
, feces
Feces
Feces, faeces, or fæces is a waste product from an animal's digestive tract expelled through the anus or cloaca during defecation.-Etymology:...
, and scent gland secretions.