The southern hairy-nosed wombat (Lasiorhinus latifrons) is one of three extant species of wombats. It is found in scattered areas of semiarid scrub and mallee from the eastern Nullarbor Plain to the New South Wales border area. It is the smallest of all three wombat species. The young often do not survive dry seasons. It is the state animal of South Australia.

Among the oldest southern hairy-nosed wombats ever documented were a male and a female from Brookfield Zoo just outside Chicago. Their names were Carver, who lived to be 34, and his mother, Vicky, who lived to be 24. In South Australia in 2010, a tame wombat named Wally was also reported as having reached the age of 34. Hamlet, a wombat at the Toronto Zoo, similarly died at age 34.

Taxonomy

English naturalist Richard Owen described the species in 1845. There are three synonyms:

  • Phascolomys lasiorhinus Gould, 1863
  • Lasiorhinus mcoyi Gray, 1863
  • Phascolomys latifrons Owen, 1845 It is also plantigrade. The body length ranges from with a body mass ranging from . The head is robust and flattened and the ears are pointed. The snout resembles that of a pig. Also, unlike the northern hairy-nosed wombat, the southern hairy-nosed wombat's nasal bone is longer than the frontal bone. Much of the southern hairy-nosed wombat's diet is Austrostipa nitida, which grows around its warren complex and is trimmed as it grazes. As such, the southern hairy-nosed wombat produces very dry faeces, with water contents as low as 40%. It has been estimated that the microbial fermentation of fibre in the wombat gut accounts for >60% of the host's daily energy requirements. Recent molecular research has shown that the diversity and composition of these gut microbial communities vary along the gastrointestinal tract, with differences between the proximal and distal colon sites correlating with where the bulk of microbial fermentation occurs. It has also been shown that captivity can drastically impact the diversity and composition of wombat gut microbes, and that different wild populations harbour different gut microbial communities.

The harsh environment in which the southern hairy-nosed wombat lives is further reflected in its energetics. In captivity, their standard metabolic rate was found to be 130 kl/kg^0.75 per day, which is very low compared to most placental animals and other marsupials.

Biology

Burrow system and activities

left|thumb|Example wombat warren, with multiple entries visible.

Southern hairy-nosed wombats dig and live in burrows which they connect into warrens with many entrances. These warrens are their prime refuges and are shared by up to 10 individuals. It leaves its new burrow backwards and pushes out soil with all its paws. Wombats move between burrows and even warrens. Male wombats are territorial towards wombats from other warrens, possibly to defend food resources and the warren refuges. Warrens can make surface conditions in habitats of low humidity and high temperatures better for the wombat. In the evening, wombats leave their burrows as the ambient temperature and burrow temperature are the same. In the early morning, when the surface temperature is lower, they retire.

Mating and reproduction

The breeding of the southern hairy-nosed wombat occurs when their favoured food is at its peak growth rates. Their reproduction relies on the winter rainfall, which germinates the grasses. This study found that the diversity and composition of microbes in the pouch correlated to the reproductive status of the host. The diversity of microbes dropped drastically when pouch young were present, or when the mother was reproductively active. One interpretation of this result is that the wombat can filter which microbes are able to live in the pouch through the use of antimicrobial peptides and/or other means. This could be important for the health of the joey, as marsupials are born very early compared to placental mammals and thus lack an adaptive immune system. Further research is also underway to determine whether the pouch microbes that survive host filtering play beneficial roles for the protection and development of the wombat pouch young.

Communication

Southern hairy-nosed wombats use vocalisations and scents for communication. While most communication between wombats occurs through olfaction and scent-marking, as they do not often encounter each other directly, The species was listed as Near Threatened by the IUCN in 2016, because "many subpopulations are now isolated and may be non-viable" but has since been updated. Wombats were hunted by aboriginal people for their meat. However, capturing a wombat takes considerable time and energy, so they were not hunted too frequently. The indigenous people of Australia value the wombat culturally and keep their local wombat populations healthy by hunting wombats in other areas. Their digging can destroy crops and can increase the risk of livestock breaking their legs by falling through their burrow systems. Competition between livestock, rabbits, and wombats can lead to overgrazing. Overgrazing and the spread of invasive weeds in some areas has led to the flora being dominated by annual grass and weed species, from which wombats cannot get enough of their metabolic needs, resulting in reports of emaciation and mass starvation. The competition from introduced rabbits threatens the survival of wombats.