Northern hairy-nosed wombat
What is the conservation status of the northern hairy-nosed wombat?
Common name: northern hairy-nosed wombat
Scientific name: Lasiorhinus krefftii (Lasio = hairy; rhinus = nose; krefftii = after Gerard Krefft, Director of the Australian Museum from 1864-1874
Family: Vombatidae (wombats)
The northern hairy-nosed wombat is listed as:
- Endangered in Queensland under the Queensland Nature Conservation Act 1992
- Critically Endangered nationally under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999
- Critically Endangered internationally under the International Union for the Conservation Of Nature (IUCN) Redlist of Threatened Species, which lists species at a global level.
It might have already been in decline when Europeans settled, and was probably the least common of the three wombat species at that time.
Since then, competition for food from introduced grazing animals, such as sheep, cattle and rabbits - particularly during droughts – has been the main reason for the species rapid decline since European arrival in Australia.
Conservation status change of the northern hairy nosed wombat
On 15 February 2018, the federal Department of the Environment and Energy (DoEE) upgraded the conservation status of the NHW from Endangered to Critically Endangered under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC). The upgrade to Critically Endangered does not indicate a lack of success in ongoing conservation efforts of the species. The change occurred as part of a process by DoEE, State and Territory conservation agencies to align the categories for threatened species in Australia with those used by the International Union for Conservation of Nature’s (IUCN) Red List of Threatened Species.
How many species of wombats are there in Australia?
Australia has three species of wombat: the common wombat, northern hairy-nosed wombat and southern hairy-nosed wombat. The common wombat occupies coastal and high country areas in south-eastern Australia, whereas the hairy-nosed wombats are more arid-adapted. The southern hairy-nosed wombat is found in semi-arid country across southern Australia, while the northern hairy-nosed wombat used to occur through inland eastern Australia from northern Victoria to north Queensland.
Northern hairy-nosed wombat
The largest of the three wombat species is the northern hairy-nosed wombat, which averages about 32kg and reaches more than one metre in length. Compared with the common wombat, northern hairy-nosed wombats have softer fur, longer and more pointed ears and a broader muzzle fringed with fine whiskers. They are generally nocturnal but will sun themselves on winter mornings and afternoons. At Epping Forest National Park, northern hairy-nosed wombats are known to have lived for at least 26 years.
Southern hairy-nosed wombat
The southern hairy-nosed wombat is the smallest wombat species, with adults averaging about 26kg. It has a broad hairy nose, long ears and soft grey-brown fur. There is often a white patch on the nose and chest. Southern hairy-nosed wombats are the most arid-adapted wombats.
Common wombats, also known as bare-nosed wombats, have a bare pointed nose, small ears and coarser brown fur. They average about 30kg in weight (22–39kg). Common wombats are nocturnal during the summer, but in winter often come out of their burrows during the day to feed and sun themselves.
How many northern hairy-nosed wombats are in Epping Forest National Park?
At the last census in 2016, there was an estimated population of 240 northern hairy-nosed wombats at Epping Forest National Park. This consisted of nearly equal numbers of male and female wombats. With the current population of 10 at Richard Underwood Nature Refuge, it is estimated there are approximately 250 northern hairy-nosed wombats in the wild.
Until 2000, wombat numbers were determined by trapping the species. Trapping to estimate numbers was a lengthy and disruptive process for the wombats, although it provided useful data on health and reproductive status. Since 2000, the hair census technique has been used to produce wombat population estimates. The technique relies on collecting wombat hair on strips of double-sided sticky tape placed across the entrance to active burrows. Tapes with hair are collected every morning for seven mornings, processed at Epping Forest National Park and sent to a laboratory for extraction of the DNA. This provides data on the genotype and sex of the wombat that the hair samples came from. If the wombat has been previously trapped, this data can be matched to its existing genotype. The data are then cross-checked and analysed by a statistician to produce a population estimate.
What do northern hairy-nosed wombats look like?
Wombats are heavily built animals with a broad head and short solid powerful legs. They have strong claws to dig their burrows, where they live much of the time.
When wombats walk, their long behinds sway from side to side. This feature, combined with a large head and habits such as curling up to rest on their sides or sitting on their haunches with their forepaws folded in front, make wombats appear slow and clumsy.
However, appearances are deceptive. Wombats can move fast—up to 40 km/h over a short distance.
Where do northern hairy-nosed wombats live?
Fossil records show that northern hairy-nosed wombats were once widespread, living in Victoria, New South Wales and Queensland. However, since European settlement, this species has only been found in three locations—the Deniliquin area in southern New South Wales, the Moonie River area in southern Queensland, and the Epping Forest area in central Queensland.
The distribution of wombat species in Australia
Epping Forest National Park is located in inland central Queensland. It is 3160 hectares of open eucalypt woodland and brigalow communities and was gazetted in 1971.
A second colony of northern hairy-nosed wombats was established in 2009 at Richard Underwood Nature Refuge at Yarran Downs near St George in southern Queensland. The nature refuge was gazetted on the 27 November 2008, and protects about 105 hectares of eucalypt woodland on old river levees. There is an additional area within the predator-proof fence which is an environmental reserve. The first northern hairy-nosed wombats were flown there in July 2009. Additional wombats were added in 2010 and the first breeding occurred in 2011.
What is the habitat of northern hairy-nosed wombats?
Northern hairy-nosed wombats require deep sandy soils, in which to dig their burrows, and a year-round supply of grass, which is their primary food. These areas usually occur in open eucalypt woodlands.
Wombats dig burrows that they rest in during daylight hours, but not all soils are suitable for burrows. At Epping Forest National Park, northern hairy-nosed wombats construct their burrows in deep, sandy soils on levee banks deposited by a creek that no longer flows through the area. They will forage in areas of heavy clay soils adjacent to the sandy soils, but do not dig burrows in these areas, which become water-logged in the wet seasons. At Epping Forest National Park, burrows are often associated with native bauhina trees, Lysiphyllum hookeri. This tree has a spreading growth form and it roots probably provide stability for the extensive burrows dug by northern hairy-nosed wombats.
What does the burrow of a northern hairy-nosed wombat look like?
A northern hairy-nosed wombat burrow can be spotted by the mound of dug-out sand at the entrance, which can be more than one metre high and several metres long. A ‘runway’ passes through the mound and leads to the burrow entrance. Wombats dig the burrow with their forepaws, and throw loose sand behind them with their forepaws and hind feet. They then walk backwards out of their burrow to bulldoze the sand clear. A northern hairy-nosed wombat will mark the entrance and mound near its burrow with dung, splashes of urine and scratches.
Researchers at Epping Forest National Park have mapped several northern hairy-nosed wombat burrows. The largest mapped burrow contained more than 90 metres of tunnels and six entrances. Major burrows average three to three and a half metres deep. The tunnel is only just wide enough for a wombat to pass—at a little less than half a metre. Temperatures in the burrows are remarkably stable and do not vary by more than 5–6°C each day. Even on cold winter nights when temperatures above ground drop below zero, burrow temperature will not drop below about 12°C. On hot summer days when outside temperatures top 40°C, deep burrow temperatures do rise above 28°C.
Humidities in deep burrows are higher than outside humidities. By breathing moist air in their burrows, northern hairy-nosed wombats conserve moisture in hot dry times.
Map of Burrow 128 at Epping Forest National Park. The burrow contained 53 metres of tunnels at an average depth of 2.35m. Maximum depth was 2.7m. The burrow was mapped by drilling a 50mm diameter 'porthole' near the burrow entrance. A camera was inserted to determine the direction of the burrow and the next porthole was drilled, and so on, until the end was reached. (Map courtesy of Glenn Shimmin).
Burrows are popular with other animals such as swamp wallabies, echidnas and goannas, which rest in the burrows during hot weather.
What do northern hairy-nosed wombats eat?
Northern hairy-nosed wombats eat almost 100% native and introduced grasses. They eat leaves rather than stems, which provide the wombats with good nutrition.
They feed for an average of six hours a night in winter and two hours in summer. By comparison, an eastern grey kangaroo of similar size needs to feed for about 18 hours a day. This is because the wombats' cool, humid burrows help them to conserve energy. Northern hairy-nosed wombats will only come out to feed at night and only when it's not too cold or too hot and dry.
Radio-tracking has shown that northern hairy-nosed wombats feed over a fairly small area for an animal of their size—about 27 hectares.
Winter (dry season) feeding areas are larger than summer (wet season) areas due to the lower availability of food. There is no difference in size between the areas used by males and females.
Wombats’ teeth continue to grow all their life. They grow from the roots at the same rate as they are worn through use. This means even a very old wombat still has all its strong teeth and is capable of grinding its food very finely.
Even in droughts, adult northern hairy-nosed wombats stay in generally good health and body condition. This is because of their ability to conserve energy and water in the stable environment of their burrows and by only venturing out when conditions are optimal.
At Epping Forest National Park and Richard Underwood Nature Refuge supplementary food and water stations have been installed. These are mostly visited by wombats in the dry seasons and not all northern hairy-nosed wombats will use them.
How do northern hairy-nosed wombats breed?
Based on the southern hairy-nosed wombat, female northern hairy-nosed wombats are likely to be sexually mature at about 2.5 years old and males at about 3 years old.
At Epping Forest National Park, most young are born in summer between November and April. They are in the pouch for eight to nine months. The exact time young wombats spend with their mothers is unknown, but it's probably about one year.
The timing of births means that young wombats start eating green nutritious grass during summer (the wet season). Between 50 and 80% of females breed in good years, giving birth to one wombat at a time.
Breeding rates fell during a drought through much of the 1990s. Better than average rainfall at Epping Forest National Park from 1996 to 2000 turned things around and very good rains in 2009/10 have provided good breeding conditions on the park. Camera and footprint monitoring in recent years have indicated that there is a significant number of young wombats in the population.
What are the threats to northern hairy-nosed wombats?
- Small population size: A threat to the northern hairy-nosed wombat's survival is the low number of wombats and that, until recently, all occurred in a single population. Small populations are much more susceptible to local catastrophes (flood, fire, disease) and loss of genetic diversity and inbreeding, than large populations.
- Predation: In 2000 and 2001, despite the presence of a regular baiting program, at least ten northern hairy-nosed wombats were killed by wild dogs. This equates to nearly 10% of the population at that time. In response to this threat, the Queensland Government built a 20km long predator-proof fence around all wombat habitat at Epping Forest National Park in 2002 to permanently protect the population.
- Competition for food: The main competitor for food of the northern hairy-nosed wombats within the enclosure at Epping Forest National Park is the eastern grey kangaroo.
- Disease: Diseases, such as toxoplasmosis (found in cat faeces) or mange, are potential threats to the wombats.
- Floods: Floods are also a potential threat. In January 2008, Epping Forest National Park was isolated by the floodwaters that covered much of central Queensland. The Belyando River normally flows some 10km to the west of Epping Forest National Park, but at the flood's peak the Park was in the middle of a vast inland sea, with water from the river flowing through the western boundary and wrapping around the park. Anxious Queensland government officers conducted a helicopter inspection during and after the flood and were relieved to find that the predator-proof fence had withstood the force of the flood, and that most of the wombat burrows appeared to be on elevated ground above the water level.
- Drought: Drought, such as the six year drought in the 1990s, slows reproductive output and reduces the body condition and survival rates of existing members of the wombat population.
- Wildfire: The threat of a wildfire for wombats is not the fire itself—they are well protected in their deep burrows—it is the loss of their food supply during the fire. Maintaining a good fire break system on the park and burning periodically to create a mosaic of burned and unburned areas is the best strategy for protecting the wombats from the effects of a major wildfire.
- Loss of habitat: The habitat at Epping Forest National Park and Richard Underwood Nature Refuge is well protected. However, loss of habitat through tree clearing and habitat alteration means that there are a limited number of places in which to establish new population of northern hairy-nosed wombats.
The management of northern hairy-nosed wombats at Epping Forest National Park.
As the majority of the northern hairy-nosed wombats live in Epping Forest National Park, this population is critical for the survival of the species. The following management actions are undertaken to conserve the wombats and their habitat:
- research and monitoring of the wombats
- fire management
- maintenance of the predator-proof fence
- control of predators and competitors
- weed control.
The Xstrata reintroduction project
There is a significant risk that one natural event such as fire, flood, drought or disease could wipe out the entire species whilst there remained only one population at Epping Forest National Park. Therefore, a second colony was needed to minimise the risk of extinction. In order to establish a second colony, it was necessary to translocate wombats from Epping Forest National Park to a new site at Richard Underwood Nature Refuge.
The reintroduction of wombats to a new site was a specific objective of the Recovery plan for the northern hairy-nosed wombat Lasiorhinus krefftii 2004–2008.
Xstrata (now Glencore), a leading mining company, has sponsored the reintroduction project as part of their Corporate Social Involvement (CSI) Program.
The ongoing management actions for wombats at Richard Underwood Nature Refuge include:
- monitor the translocated wombats
- manage pests and predators
- manage weeds and fire.
Horsup A.B., and Johnson, C.N. (2008). Northern hairy-nosed wombat, Lasiorhinus krefftii. In Van Dyck. S. and Strahan, R. (ed.s), The Mammals of Australia. Reed New Holland.
On the evening of 2 March 2009, departmental Officers took TIME magazine photographer Warren Evans, his camera, and a spotlight on a mission to find the endangered northern hairy-nosed wombat holed up on Epping Forest National Park in central Queensland, Australia. What they saw was extraordinary.
TIME magazine - Wombat Love