Northern Hairy-nosed Wombat

Northern Hairy-nosed Wombat[1]
Conservation status
Critically Endangered (IUCN 3.1)[2]
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Infraclass:	Marsupialia
Order:	Diprotodontia
Family:	Vombatidae
Genus:	Lasiorhinus
Species:	L. krefftii
Binomial name
Lasiorhinus krefftii (Owen, 1873)
Northern Hairy-nosed Wombat range

The Northern Hairy-nosed Wombat (Lasiorhinus krefftii), 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. 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

Yaminons can be 35 cm high, up to 1 m long and up to 40 kg. The females are a little bit bigger than the males because they have an extra layer of fat. It is 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 their survival because they have very poor eyesight so they can smell their food in the dark. It takes about a day for a northern hairy-nosed wombat to dig a burrow with their sharp claws (The wombat's claws are about 5 cm in length).

Behaviour

The Northern hairy-nosed wombat is nocturnal, and has been known to share burrows^[4]. Its diet is made up of coarse grass and various types of roots. Its habitat has become infested with African buffel grass, which out-competes the native grasses the Yaminon prefers to feed on. One young can be born, often during the wet season. It stays in the pouch for 6-9 months, leaving its mother after a year^[5].

Phylogeny

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 Hairy-nosed Wombat shares marsupial ancestors with kangaroos and the koala.

Analogous Structures

Though the Northern Hairy-nosed wombat shares many similar structural features to that of the Marmot, these mammals are not closely related. The Marmot is a placental mammal living in such environments as mountains. Both species have long, strong claws, well designed to dig burrows. This being analogous, both species has evolved this similarity over a period of time.

Homologous Structures

A homologous structure and characteristic which is present in all Wombats, including Hairy-Nosed Wombats, have a pouch which opens at the female Wombat's rear end. This characteristic is not common among other marsupials. Having its pouch opening at its rear end is an advantage due to the wombats constant burrowing, as the risk of dirt entering the pouch and harming the offspring is very high. The pouch opening being at the Wombats rear end also provides better protection when the mother walks and runs, and also against predators.

Preservation

The Northern Hairy-nosed Wombat is listed as "endangered" by the Australian Species Profile and Threats Database (SPRAT),^[6] 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. ^[7] This second colony was established in 2008 and is also in a reserve surrounded by a predator proof fence. ^[8]

References

1. ^ Groves, Colin P. (16 November 2005). "Order Diprotodontia (pp. 43-70)". In Wilson, Don E., and Reeder, DeeAnn M., eds. Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Baltimore: Johns Hopkins University Press, 2 vols. (2142 pp.). p. 43. ISBN 978-0-8018-8221-0. OCLC 62265494. http://www.bucknell.edu/msw3/browse.asp?id=11000008. 
2. ^ ^{a b} Taggart, D., Martin, R. & Horsup (2008). Lasiorhinus krefftii. In: IUCN 2008. IUCN Red List of Threatened Species. Downloaded on 02 Sept 2009.
3. ^ Eastwood, K. (2003): Saving the northern hairy-nosed wombat. Australian Geographic No. 72, Oct.-Dec. 2003.
4. ^ http://australian-animals.net/wombat-n.htm
5. ^ http://australian-animals.net/wombat-n.htm
6. ^ "Lasiorhinus krefftii Northern Hairy-nosed Wombat". Species Profile and Threats Database. http://www.deh.gov.au/cgi-bin/sprat/public/publicspecies.pl?taxon_id=198. Retrieved 2007-01-05. 
7. ^ http://www.derm.qld.gov.au/wildlife-ecosystems/wildlife/threatened_plants_and_animals/endangered/northern_hairynosed_wombat/
8. ^ http://www.derm.qld.gov.au/wildlife-ecosystems/wildlife/threatened_plants_and_animals/endangered/northern_hairynosed_wombat/

• Underhill D (1993) Australia's Dangerous Creatures, Reader's Digest, Sydney, New South Wales, ISBN 0-86438-018-6