Southern Hairy-nosed Wombat
Encyclopedia
The Southern Hairy-nosed Wombat (Lasiorhinus latifrons) is one of three species of wombat
Wombat
Wombats are Australian marsupials; they are short-legged, muscular quadrupeds, approximately in length with a short, stubby tail. They are adaptable in their habitat tolerances, and are found in forested, mountainous, and heathland areas of south-eastern Australia, including Tasmania, as well as...

s. It is found in scattered areas of semi-arid scrub and mallee
Mallee (biogeographic region)
Mallee, also known as Roe Botanical District, is a biogeographic region in southern Western Australia. Located between the Esperance Plains, Avon Wheatbelt and Coolgardie regions, it has a low, gently undulating topography, a semi-arid mediterranean climate, and extensive Eucalyptus mallee...

 from the eastern Nullarbor Plain
Nullarbor Plain
The Nullarbor Plain is part of the area of flat, almost treeless, arid or semi-arid country of southern Australia, located on the Great Australian Bight coast with the Great Victoria Desert to its north. It is the world's largest single piece of limestone, and occupies an area of about...

 to the New South Wales
New South Wales
New South Wales is a state of :Australia, located in the east of the country. It is bordered by Queensland, Victoria and South Australia to the north, south and west respectively. To the east, the state is bordered by the Tasman Sea, which forms part of the Pacific Ocean. New South Wales...

 border area. It is the smallest of all three wombat
Wombat
Wombats are Australian marsupials; they are short-legged, muscular quadrupeds, approximately in length with a short, stubby tail. They are adaptable in their habitat tolerances, and are found in forested, mountainous, and heathland areas of south-eastern Australia, including Tasmania, as well as...

 species. The young often do not survive dry seasons. It is the state animal of South Australia
South Australia
South Australia is a state of Australia in the southern central part of the country. It covers some of the most arid parts of the continent; with a total land area of , it is the fourth largest of Australia's six states and two territories.South Australia shares borders with all of the mainland...

.

The oldest southern hairy-nosed wombats ever documented were a male and a female from Brookfield Zoo
Brookfield Zoo
The Brookfield Zoo is zoo located in the Chicago suburb of Brookfield, Illinois. The zoo covers an area of and houses around 450 species of animals....

 just outside of Chicago
Chicago
Chicago is the largest city in the US state of Illinois. With nearly 2.7 million residents, it is the most populous city in the Midwestern United States and the third most populous in the US, after New York City and Los Angeles...

. Their names were Carver, who lived to be 34, and his mother, Vicky, who lived to be 24.

Physical description

The southern hairy-nosed wombat has a stocky and robust build adapted for digging. It is plantigrade and digs with its flattened claws found on each of its 5 digits. The body length ranges 772–934 mm (30.39-36.77 in) with a body mass ranging 19–32 kg (41.8-70.4 lbs). It has a short tail that is hidden by its fur. The pelage is silky and ranges in colour from grey to tan. The second and third toes of the wombat’s hind feet are mostly conjoined, apart from their terminal joints, forming a digit with two claws which the wombat uses for grooming. The head is robust and flattened with extended, pointed ears. The snout is pig-like. The animal gets its name from the soft fur covering its rhinarium.
The wombat's incisors resemble those of rodents and have molars with a wide palate between them. All the teeth grow continuously throughout its life, which is likely an adaptation to its harsh diet. Compared to the common wombat
Common Wombat
The common wombat , also known as the coarse-haired wombat or bare-nosed wombat, is a marsupial, one of three species of wombats and the only one in the genus Vombatus. The common wombat grows to an average of long and a weight of .- Taxonomy :The common wombat was first described by George Shaw...

, the southern hairy-nosed wombat has a better developed temporalis muscle
Temporalis muscle
The temporal muscle is one of the muscles of mastication.-Structure:It arises from the temporal fossa and the deep part of temporal fascia...

 and a more reduced masseter muscle
Masseter muscle
In human anatomy, the masseter is one of the muscles of mastication.In the animal kingdom, it is particularly powerful in herbivores to facilitate chewing of plant matter.-Origin and insertion of the two heads:...

. It is also distinguished from the northern hairy-nosed wombat
Northern Hairy-nosed Wombat
The Northern Hairy-nosed Wombat , also known as the Yaminon, is one of three species of wombats. It is one of the rarest large mammals in the world and is critically endangered...

, with its nasal bone being longer than the frontal bone.

Biology and ecology

Southern hairy-nosed wombats live in Western Australia, southern South Australia, and south-western New South Wales. They inhabit semi-arid to arid grasslands and woodlands that receive 200 to 500 mm of rain per year.

Feeding and energy

Southern hairy-nosed wombats, along with other wombat species, prefer to eat tough native perennial grasses and sedges when given the choice, . However, they will eat introduced pasture species, as well as forbs and the leaves of woody shrubs when in adverse conditions. Much of the southern hairy-nosed wombat's diet is Stipa nitida, which grows around its warren complex and becomes close cropped as the wombat grazes nearby. This creates an area with a higher density of new green shoots, a sign of delayed growth of individual grass can break down when grazing on the same plant species. The teeth of the wombat can grind food to a mean particle size half that of what a Western grey kangaroo
Western Grey Kangaroo
The Western Grey Kangaroo is a large and very common kangaroo or macropod, found across almost the entire southern part of Australia, from just south of Shark Bay to coastal South Australia, western Victoria, and the entire Murray-Darling Basin in New South Wales and Queensland...

 grazing on the same species. The digestive tract of the wombat has a tiny caecum and a colon with two clearly defined parts. The anterior part is larger and acts as the main fermentation chamber and the posterior part is where water is reabsorbed. For the southern hairy-nosed wombat, the fermentation chamber is comparatively small and the posterior part is large, an adoption for its desert environment. The wombat conserves water by recycling more urea
Urea
Urea or carbamide is an organic compound with the chemical formula CO2. The molecule has two —NH2 groups joined by a carbonyl functional group....

 to the colon rather than excreting it as urine. Wombats have the lowest recorded water turnovers for herbivorous mammals. As such the southern hairy-nosed wombat produces very dry faeces with water content as low as 40%.

The harsh environment in which the southern hairy-nosed wombat lives is further reflected in its energetics. The standard metabolic rate (SMR) was measured in captivity to be 130 kl/kg^0.75 per day which is very low, being only 64% of the marsupial average or 42% of the placental mammal average. The thyroid hormone levels, which are a reflection of SMR, are the lowest recorded for any mammal. It has been calculated that the amount of forage consumed provides 2.8 times the maintenance energy needs of the wombat, which is very similar to the radio between SMR and field metabolic rates (FMR) for the koala
Koala
The koala is an arboreal herbivorous marsupial native to Australia, and the only extant representative of the family Phascolarctidae....

, greater glider
Greater Glider
The Greater Glider is a small gliding marsupial found in Australia. It is not closely related to the Petaurus group of gliding marsupials but instead to the Lemur-like Ringtail Possum , with which it shares the subfamily Hemibelideinae.The Greater Glider is nocturnal and is a solitary herbivore...

 and for the common ringtail possum
Common Ringtail Possum
The common ringtail possum is an Australian marsupial. It lives in a variety of habitats and eats a variety of leaves of both native and introduced plants, as well as flowers and fruits. These dietary factors have, over time, aided burgeoning introduced populations in New Zealand...

 during late lactation. As such, as long as there’s enough food, its preferred diet is sufficient to support the lactation of the animal. The nitrogen, water and energy needs of the wombat are very frugal and thus it is able to maintain its body mass on food of very low quality, even during droughts. It can outperform a donkey which has a lower metabolic rate, lower food intake and slower rate of passage.

Burrow system and activities

Southern hairy-nosed wombats dig and live in burrow which they connect into warrens with many interconnected entrances. These warrens are their prime refuges and are shared by up to ten individuals. When digging a burrow, a wombat sits on its hind end and uses its forepaws to dig at the earth and pushes it to the side. When the wombat leaves its new burrow, it exits backward, pushing the dirt out with all four of its paws. The central warren is surrounded by a circle of small simple burrows 100–15 m from it. Resident wombats graze as far as the perimeter burrow which also provide a temporary refuge to extend the grazing area further. They also provide a temporary refuge for young wombats that have been driven from the central warren. Wombats do not share burrows within a warren. While they show some preference for particular burrows and warrens, with females showing a greater tendency to stay near a burrow system than males do, there are no individual claims of ownership of a particular burrow. Wombats will change burrows and even warrens. There appears to be some separation of sectors of the common grazing area between members of the group in the warren. Male wombats are territorial towards other warren groups, possibly to defend food resources and the warren refuges. Trails of droppings connect the burrows together and serve to mark the territory. They also mark their territory with scent secretions from their anal scent glands by rubbing their backs and rumps on objects and. Occasionally, two males may fight to defend their territories or mates, biting the ears, flank, or rump. There is also a dominance hierarchy among males.

The burrows of a southern hairy-nosed wombat can have air temperatures within the range of 14°C in mid winter to 26°C in mid summer, the preferred thermo-neutral zone of the wombat, while the air temperatures on the surface are around 2°C to 36°C. Warrens can make surface conditions in habitats of low humidity and high temperatures better for the wombat. When a wombat forages outside and then returns, it retreats into the depths of the burrow. When it is about to emerge the following night it moves towards to the burrowing entrance but retreats if the temperatures is too high or the humidity is too low. In the evening, wombats emerge from their burrows as the outside temperature is the same as the burrow temperature. In the early morning, they return as the ambient temperature is still below the burrow entrance. They use the burrow complex to avoid the outside climate extremes and conserve water and energy by remaining within their thermo-neutral zone at all times.

Mating and reproduction

The breeding of the southern hairy-nosed wombat occurs when their favoured food is at their highest growth rates. The reproduction of wombats is affected by the amount of winter rainfall, being dependent on the germination of grasses. Between August and October, when there is enough rainfall, females ovulate and males have high testosterone levels and enlarged prostate glands. In years of low rainfall, females do not ovulate and the testosterone level of males is low their prostate glands are small. During the breeding season, dominance hierarchies among males are maintained though aggression. Copulation takes place in the warren with males remaining in one burrow and females moving among them. During copulation the male turns the female on her side and mounts her from behind, this lengthens the time of intro-mission. The gestation period of the wombat lasts 22 days and most births occur in October. When a young is born, it attaches to one of the two teats in the pouch. A young remains in the pouch for six months At this time, it is lightly furred with its eyes open and it weighing about 0.45 kg. It leaves the pouch prematurity about three months later, in July or August, and makes its first emergence out of the burrow and feeds on grass. It is not fully weaned until it is one year old and doesn’t reach full size until it is three years old. When a young is weaned, the mother can reproduce again.

Communication

Southern hairy-nosed wombats use vocalisations and scents for communication. Wombats rely more heavily on scent to communicate as direct encounter between them are rare. Wombats will investigate scents recently left by other wombats. While most communication between wombats occurs through olfaction and scent marking, wombats will emit rough coughing noises when they pass each other and will emit a more strident call to alert others when alarmed.

Status

The southern hairy wombat is listed as Least Concern
Least Concern
Least Concern is an IUCN category assigned to extant taxon or lower taxa which have been evaluated but do not qualify for any other category. As such they do not qualify as threatened, Near Threatened, or Conservation Dependent...

 by the IUCN because "While there are sporadic outbreaks of sarcoptic mange, competition with introduced herbivores, susceptibility to drought, and severe fragmentation in parts of its range, the species has a wide distribution, large population, occurs in a number of protected areas, and it is unlikely to be declining at nearly the rate required to qualify for listing in a threatened category". Wombats were hunted by aboriginal people for their meat. However, capturing a wombat takes a lot of time and energy and so they were not hunted too frequently. The indigenous people of Australia value the wombat culturally and keep their own wombat populations healthy by hunting wombats elsewhere.

Wombats can be agricultural pests. They can destroy crops when they dig their burrows and livestock may break their legs when they break through into a wombat burrow. Livestock and rabbits compete with wombats for forage and this can lead to overgrazing. Overgrazing leads to annual grass species becoming the dominant species and wombats can't get all of their metabolic needs from these. Currently the spread of rabbits throughout Australia is one of the main threats to their survival.

Populations

This species is has a patchy distribution across its range. On the Nullarbor Plain, it is abundant with estimates of between 50,000 and 100,000 in the South Australian portion but no population estimates for Western Australia. 10,000-15,000 wombats appear to inhabit the Murray Lands, but drought and sarcoptic mange likely caused the population to decline by 70% here since 2002. In the Yorke and Eyre Peninsulas the population is highly fragmented.
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