A nocturnal species, the southern hairy-nosed wombat resides in a burrow during the day (3). The complex burrow network, or warren, consists of several tunnels with numerous entrances and leaf-lined resting chambers. Burrows are dug to a maximum depth of about two metres and can have tunnels up to thirty metres long (2). Often five to ten southern hairy-nosed wombats share a burrow system, with about equal proportions of both sexes (3).
The superb architecture of the burrow allows the southern hairy-nosed wombat to cope with the exceptionally high temperatures in its habitat. While air temperatures outside the burrow may exceed temperatures the wombat can tolerate, especially during summer, the temperature inside remains a constant 26 degrees Celsius in summer and 14 degrees Celsius in winter (3).
When the cooler temperatures of the night arrive, the southern hairy-nosed wombat leaves its burrow and begins foraging. This species feeds on tough native grasses, with young shoots of balcarra grass (Austrostipa nitida) being one of the main components of its diet (3). This grass grows around the wombat’s warren complex, and “grazing halos” of cropped grass often form around the warrens (4).
The southern hairy-nosed wombat has an extremely small home range of only four hectares, partly because it has very low energy requirements, a necessary adaptation to compensate for the low-energy content of its grassy diet (3). The southern hairy-nosed wombat has an astoundingly low metabolic rate, and when resting in its burrow it can slow it to only two-thirds of its normal rate (2). Conserving water is also important in the southern hairy-nosed wombat’s harsh, arid habitat, and this species is so effective at conserving the water it obtains from food that it does not need to drink (3).
Due to the harshness of their environment, wombats have adapted so that breeding only occurs when there are adequate resources, and mating may not occur at all during periods of drought (3). In years with sufficient rainfall and grass growth, the southern hairy-nosed wombat breeds in spring, with the majority of births occurring in October (2). Mating takes place in the burrow, with the female giving birth to a single young, or ‘joey’, after a 22 day gestation period. A separate nursery burrow is used for giving birth and raising the young (2).
The joey is tiny and hairless at birth and weighs just one gram. However, it has well-developed forelimbs that enable it to climb unassisted into the female’s pouch and attach itself to a teat (2), where it remains permanently attached for the first few months of life (3). The wombat’s pouch is directed backwards to prevent the joey from being covered in soil when the female is digging (3). The joey first emerges from the pouch when it is six months old (3), and permanently leaves the pouch three months later (2).
The southern hairy-nosed wombat is not fully weaned until it is one year old, and is not fully grown until three years of age. Female wombats can produce at most one joey every two years (3). Although many wombats fail to survive the vulnerable first one to three years of life, the southern hairy-nosed wombat can have a considerably long lifespan, living to over 15 years in the wild (4).