The northern hairy-nosed wombat (Lasiorhinus krefftii), is one of three species of wombats. It is one of the rarest large mammals in the world and is critically endangered. Its historical range extended across New South Wales, Victoria, and Queensland as recently as 100 years ago, but it is now restricted to one place, a 3-km² range within the 32-km² Epping Forest National Park in Queensland. In 2003, the total population consisted of 113 individuals, including only around 30 breeding females.^[3]

Description

Northern hairy-nosed wombats can be 35 cm high, up to 1 m long and weigh up to 40 kg. The females are somewhat larger than the males because they have an extra layer of fat. They are slightly larger than the common wombat and able to breed somewhat faster (two young every three years). The northern hairy-nosed wombat's nose is very important in its survival because it has very poor eyesight, so it can smell its food in the dark. It takes about a day for a northern hairy-nosed wombat to dig a burrow with its sharp, about 5-cm-long claws.

Behaviour

The northern hairy-nosed wombat is nocturnal, and has been known to share burrows.^[4] Its diet is made up of coarse grasses and various types of roots. Its habitat has become infested with African buffel grass, which outcompetes the native grasses on which the wombat prefers to feed. One young is born at a time, often during the wet season. It stays in the pouch for six to 9 months, leaving its mother after a year.^[4]

Taxonomy

Nomenclature

The genus name Lasiorhinus comes from the Latin lasios (hairy or shaggy) and rhinus (nose).^[5] The widely accepted common name is northern hairy-nosed wombat, although in some older literature it is referred to as the Queensland hairy-nosed wombat.^[6]

Classification

The northern hairy-nosed wombat shares its genus with one other extant species, the southern hairy-nosed wombat. The other extant species in the Vombatidae family, the common wombat, is in the Vombatus genus. Both Lasiorhinus species are very similar, differing morphologically from the common wombat by their silkier fur, broader hairy noses, and longer ears.^[7]

Placental and marsupial mammals are an example of divergent evolution, an evolutionary concept occurring when a single group of organisms splits into two groups and each group evolves in increasingly different directions. The wombat, with all marsupials, diverged from placental mammals during the Cretaceous. The koala is the most closely related marsupial to wombats and is categorised in the same suborder, Vombatiformes.^[8]

Preservation

The northern hairy-nosed wombat is listed as "endangered" by the Australian Species Profile and Threats Database (SPRAT),^[9] and "critically endangered" by the IUCN.^[2] Its range is restricted to about 300 ha (750 acres) of the Epping Forest in east-central Queensland, 120 km northwest of Clermont. A two-metre-high, predator-proof fence was constructed around 25 km² of the park in 2000. Recently, a second colony of wombats has been established at Richard Underwood Nature Refuge at Yarran Downs near St George in southern Queensland.^[10] This second colony was established in 2008 and is also in a reserve surrounded by a predator-proof fence.^[10]

References