80.
Malagasy Giant Jumping Rat
(Hypogeomys antimena)
EN
Overview
This rabbit-like mammal is the largest rodent in Madagascar. It has long pointed ears and long hind feet which are used for jumping. The species occupies a niche which is filled by rabbits in other parts of the world. Unusually for rodents, the Malagasy giant rat is monogamous, forming lifelong pair bonds. Since females only have one or two offspring per year, the species does not have the potential for rapid population growth characteristic of many other rodents. It is therefore particularly vulnerable to predation by dogs, and the habitat loss and fragmentation that is occurring throughout its range.
Urgent Conservation Actions
Habitat protection, and investigation into impact of introduced predators, with control methods brought in where necessary.
Distribution
Western Madagascar.
Associated Blog Posts
12th Mar 12
A few weeks ago in February, two new Malagasy giant jumping rats (Hypogeomys antimena) were born at London Zoo. This is the desired result of a captive breed...  Read

Media from ARKive
ARKive image - Malagasy giant rat
ARKive image - Malagasy giant rat, close up
ARKive image - Malagasy giant rat in log
ARKive image - Malagasy giant rat
ARKive image - Malagasy giant rat, side view
ARKive image - Malagasy giant rat
ARKive image - Malagasy giant rat on hind legs
ARKive image - Malagasy giant rat standing
ARKive image - Malagasy giant rat
ARKive image - Malagasy giant rat
Evolutionary Distinctiveness
Order: Rodentia
Family: Nesomyidae
The Malagasy giant jumping rat belongs to the subfamily Nesomyinae, which is an extremely diverse group of around 23 muroid rodents endemic to Madagascar. This group is believed to have evolved in East Africa during the early Miocene (26 million years ago), and to have become isolated on Madagascar in the late Miocene (around 7 million years ago). There are 9 small genera within the Nesomyinae. The Malagasy giant jumping rat is the only living species in the ‘jumping rat’ genus Hypogeomys. A second much larger and now extinct species, H. australis, has been described from subfossil remains found in the southeast of Madagascar.
Description
Size: 
Head and body length: 300-350 mm
Tail length: 210-250 mm
Ear length: 50-60 mm
Weight: 1-1.5 kg
The Malagasy giant rat is the largest rodent in Madagascar. It is a rabbit-like species, with long pointed ears and long hind feet which are used for jumping. Its rough fur is grey, greyish-brown or reddish above; the head is darkest. The underparts, limbs, hands and feet are white. The tail is dark and covered with stiff, short hairs. The usual method of locomotion is on all fours, although these rats can hop on their hindlegs and jump up to a metre into the air when faced with danger.
Ecology
This species occupies a niche which is filled elsewhere in the world by rabbits. It builds long, deep burrows in which it sleeps during the day. Typical burrow complexes are 5 m in diameter and have 1-6 holes. The entrances to these holes are usually kept plugged with a barrier of soil and leaves, which the animals have to excavate and re-seal each time they pass in and out. At night the species emerges to forage for food. It is believed to feed mainly on fallen fruit, seeds and leaves. Unusually for rodents, this species is monogamous – a mated pair and their most recent offspring live together in a single burrow. Pairbonds apparently last until one mate dies. The pairs defend an exclusive territory of around 3.5 ha, marking their boarders with urine, faeces and scent gland deposits. The minimum population density in favourable habitat is 48/ha. Males reach sexual maturity at one year, at which time they leave the parental burrow and set up their own territories. Females mature at two years, but usually remain with their parents for at least one breeding season subsequent to this. Reproduction occurs in the rainy season (December – March) and females usually give birth to one or occasionally two young. Females are thought to be capable of giving birth twice during the reproductive season when food is plentiful, although this rarely happens. Infant mortality is high, with only around 50% of young surviving to adulthood. The species is an important prey species for the fossa (Cyprtoprocta ferox) and a ground boa constrictor (Acrantophis dumerili). They also play an important role in seed dispersal, and aerate the soil though their fossorial behaviour. There is little information available on the lifespan of this species in the wild. In captivity giant jumping rats have a life expectancy of around 5 years.
Habitat
The species only occurs in coastal dry deciduous forest mixed with baobabs resting on sandy and lateritic soils. It avoids degraded areas and secondary forests with open canopy and dense undergrowth.
Distribution
Now confined to an area of 200 km² of small forest fragments northeast of the town of Morondava, on the west coast of Madagascar. The population is divided into two subpopulations separated by the Mandroatra River.
Population Estimate
The species only occurs at low densities and appears to be rare throughout its limited range. Numbers are estimated at around 11,000.
Population Trend
Decreasing.
Status
Classified as Endangered (EN B1ab(iii,v)) on the 2010 IUCN Red List of Threatened Species.
Threats
This species has declined rapidly as a result of habitat loss and fragmentation, and predation from introduced species such as dogs. Its habitat is decreasing at an alarming rate due to illegal and commercial logging, slash-and-burn agriculture, charcoal production and burning for the creation of cattle pasture. The species appears to be very sensitive to human activity and will move away from areas of disturbed habitat. These threats are exacerbated by the extremely low reproductive rate of the species. Unlike most rodents, female giant jumping rats only have one or two offspring per year. Therefore the species does not have the potential for rapid population growth characteristic of many other rodents. Populations are expected to continue to decline over the next 100 years even if further habitat decline and mortality by roaming dogs can be stopped.
Conservation Underway
The northern subpopulation is severely threatened. It is currently without any protection, and is not connected to the southern population. Most of the southern population lies in the 12,5000 ha Kirindy Forest, a government-owned forest concession where sustainable forestry techniques have enabled many of the native species to survive. Research into the behavioural ecology of this species has been carried out for a number of years at the research station of the German Primate Centre (DPZ, Götingen, Germany) in the Kirindy Forest. The Durrell Wildlife Conservation Trust is working with the local Malagasy to conduct detailed surveys into the status and threats facing the wild population. It is also involved in a community education programme which aims to raise awareness of conserving the species’ forest habitat, and is working to get a part of the species remaining habitat declared an official protected reserve. In 1990, DWCT established a captive breeding programme for the species to safeguard against possible extinction in the wild. This programme has proven successful and there are now more than 50 giant jumping rats in twelve different institutions throughout the world, including London Zoo.
Conservation Proposed
Since the species does not appear to tolerate human disturbance it is crucial that remaining areas of pristine habitat are protected before it is too late. The impact of introduced predators, such as dogs, on the population needs to be investigated, and methods of control brought in where necessary.
Zoo population

There are Malagasy giant jumping rats resident at ZSL London Zoo.

References

Durbin, J. & Goodman, S. 2008. Hypogeomys antimena. In: IUCN 2010. IUCN Red List of Threatened Species. Version 2010.4.www.iucnredlist.org. Downloaded on 14 November 2010.

Durrell Wildlife Conservation Trust

Nowak, R.M. 1999. Walker's Mammals of the World. Sixth edition. The Johns Hopkins University Press, Baltimore and London.

Sommer, S. 2001. Reproductive ecology of the endangered monogamous Malagasy giant jumping rat, Hypogeomys antimena. Mammalian Biology 66: 111-115.

Sommer, S., Volahy, A. T. and Seal, U. S. 2002. A population and habitat viability assessment for the highly endangered giant jumping rat (Hypogeomys antimena), the largest extant endemic rodent of Madagascar. Animal Conservation 5: 263-273.

Distribution map based on data provided by the IUCN Global Mammal Assessment.

if you can provide new information to update this species account or to correct any errors, please email us at info@edgeofexistence.org


Forum comments

There are as yet no comments for this species.

Add a comment

You must log in to post. If you don't have a login, it's easy to register.