What is the conservation status of common wombats?
There are three subspecies of common wombat: Vombatus ursinus platyrhinus which is found on the southeastern Australian mainland, Vombatus ursinus tasmanicus which is found in Tasmania and Vombatus ursinus ursinus which was once found throughout the Bass Strait islands but is now restricted to Flinders Island and has been introduced to Maria Island.
The common wombat (Vombatus ursinus
) is not listed as threatened in Tasmania or Australia under the Tasmanian Threatened Species Protection Act 1995
or the Australian Environment Protection and Biodiversity Conservation Act 1999
The Flinders Island subspecies of common wombat (Vombatus ursinus ursinus) is listed as Vulnerable under the Australian Environment Protection and Biodiversity Conservation Act 1999 on the basis that its restricted geographic distribution presents a threat to the survival of the subspecies.
Wombats are protected in Tasmania under the Tasmanian Nature Conservation Act 2002 and permits are required to take and possess this species.
Are wombat numbers declining?
DPIPWE has been monitoring counts of mammals along spotlight survey transects in eastern, northern, southern and central Tasmania for several decades. Wombat counts have generally increased across these regions between 1985 and 2016. The reasons for this increase are not clear but may relate to changes in land use and management practices and reduced predation by Tasmanian devils (which have declined in numbers due to facial tumor disease).
DPIPWE spotlight counts and monitoring by the University of Tasmania have shown that the population of wombats in the area immediately to the west of the Tamar River and in Narawntapu National Park reduced markedly between 2010 and 2016. The University of Tasmania found that the wombat population in Narawntapu National Park reduced by 94% during that time. The cause of this decline has been attributed to a severe outbreak of mange. Local population declines associated with mange have also been reported from mainland Australia.
Although mange has been present in many parts of Tasmania over many decades, it has not resulted in widespread declines in numbers of wombats. Understanding why outbreaks of mange occur in some areas and cause significant losses of wombats is the topic of ongoing research.
What is mange?
Sarcoptic mange is a skin infection in mammals that is caused by a burrowing parasitic mite, Sarcoptes scabiei. It affects more than 100 mammalian species worldwide, including humans and dogs. The disease is referred to as scabies in humans and mange in other species. Australian native mammals that are known to be affected by mange include ringtail possums, brown bandicoots koalas and common wombats. Mange infection in an animal can result in aggressive scratching, hair loss, skin thickening and crusting, skin discoloration, open wounds (from scratching), weight loss, and in severe cases, death (as a result of secondary infection and suppressed immune system).
Where did mange originally come from and how did it get here?
It is thought that humans were the original host of sarcoptic mites, who then passed it on to their domestic animals, with subsequent spill-over events to wildlife. Current evidence strongly indicates that mange was introduced to Australia (and Tasmania) by European settlers and their domestic animals about 200 years ago. The current distribution of mange disease is considered worldwide.
Why are wombats more prone to mange and does it kill them?
Of the native Australian mammal species known to be affected by mange, wombats appear to be most impacted.
Wombat burrows are believed to have good conditions for the survival of mites and the transfer of mites between wombats. Laboratory studies have shown that cool, humid conditions lead to the longest survival of mites away from their host — such conditions can occur in wombat burrows.
The disease generally occurs at low prevalence, but higher rates of incidence and impact can occur within localised populations. These localised outbreaks may be associated with high wombat densities, during periods of drought or nutritional stress. In severe cases sarcoptic mange can kill individual wombats and can cause a substantial reduction in wombat numbers in localised areas.
How does mange spread?
In wombats, most transmissions are thought to occur as a result of burrow sharing. While adult wombats are mainly solitary when above ground, their home ranges overlap with other wombats and burrows can be used by more than one wombat, often at separate times but occasionally simultaneously.
Mites can persist in the burrows in the absence of wombats for up to three weeks. This persistence by the mites provides a reservoir for the disease to spread to other wombats. The strains of mites are largely specific to their host species, but spill-over events of infection transmission can occur between species.
Other mammal species entering infected wombat burrows could also spread the disease.
Is mange spreading and how widespread is mange in wombat populations?
Sarcoptic mange has been reported to be present throughout the common wombat’s entire geographic range, including Tasmania. A national survey revealed mange to be present in 90% of common wombat populations and over many decades wombats with mange have been reported from a range of locations across Tasmania.
In general, prevalence of mange within wombat populations is often low with little or no impact on their population numbers However, in some localised areas where prevalence is high and outbreaks occur, such as Narawntapu National Park and surrounding areas, the impacts can be severe.
Increased monitoring of wombats in Tasmania is being undertaken by DPIPWE in partnership with Conservation Volunteers Australia and the University of Tasmania to better understand the extent of mange within wombat populations across the State.
Can mange be eradicated?
No, there is no method of eradicating mange from the wild at a population level. Individual wombats and other animals may be treated to remove their mites.
Can mange-infected burrows be fumigated?
There are currently a number of practical challenges associated with burrow fumigation that make this technique not yet feasible. Fumigating burrows could result in exposure and adverse animal welfare outcomes for wombats that may occupy fumigated burrows. It is unknown if fumigants would sufficiently penetrate the environments in burrows that mites occupy (such as bedding chambers). There is currently no simple technique to sample mange mites from burrows to test if fumigation is successful. Burrows can have multiple entrances and this may impact capacity to successfully fumigate a burrow system to eliminate the mange mite. Where wombats occur, there are often numerous burrows scattered across the landscape, making it difficult to determine which burrows should be fumigated and expensive to consider fumigating all of them.
Will mange cause wombats to go extinct?
There is very little evidence to suggest that mange will cause common wombats to go extinct. Mange has been present in Australia for over 200 years. Although mange has caused severe local population declines in Australia, it has not led to a widespread reduction in the numbers of common wombats. There have been published reports of periodic local population declines of wombats since the 1930s on the Australian mainland. In Tasmania, monitoring of common wombats over the past 30 years suggest that numbers have generally increased despite a local decline in wombats between 2009 and 2017 in the area west of the Tamar River.
The Tasmanian wombat population will continue to be monitored to detect signs of population.
How do I know if a wombat has mange?
Signs of mange infection include itching, scratching, skin thickening and crusting, loss of hair and body condition. Mange infections usually present as crusty skin lesions on the sides and legs of wombats. Scabs can also form around the eyes and ears, impacting on the animal’s sight and hearing.
However, not all skin conditions on wombats can be attributed to mange. Wombats may become aggressive towards each other resulting in wounds. These attack wounds, which may look like mange in appearance, are usually on the wombat’s rump area whereas the back and rump are usually the least affected areas on a wombat with mange.
Wombat showing severe condition resulting from mange
copyright: K. Simpson
How long does it take for the infection to spread?
Typically, the first clinical signs of mange develop 1–3 weeks after exposure to the parasites; more chronic signs appear after 4–5 weeks. In severe cases, death may occur as a result of secondary bacterial infection 2–3 months after infection. The severity of infection may vary with initial doses of exposure as well as the condition and health status of the host.
Why are some wombats severely affected and not others?
The reasons why some wombats become infected and others do not are poorly known. Sarcoptic mange occurs in common wombat populations across most of their range, but the disease varies widely in its expression and impacts on local populations. Wombat densities, environmental conditions and wombat health are all thought to have an influence on whether or not wombats become infected with mange.
It is commonly reported that increased rates of mange disease in wombats are often associated with high wombat densities, and periods of environmental stress, e.g. drought and winter conditions. Expression of disease may be seasonal, resulting from increased mortality of mites due to adverse conditions (hot and dry). The overall health and condition of individual wombats also varies and the disease may affect individual wombats that are already compromised compared to healthy robust individuals.
Does mange affect the behaviour of wombats?
Yes, mange affected wombats are more active outside of their burrows for more extended periods compared to healthy wombats, and spend more time above ground during daylight hours. Mange affected wombats spend less time walking, and more time scratching, foraging and drinking than healthy wombats. They have a slower feeding rate and they are generally in poorer body condition. As a result of scabs around the face in more severe cases, the wombats may appear deaf and / or blind, and may not be very alert or responsive.
When are infected wombats observed most often?
Wombats with mange can be observed at any time of day; however, an Australian mainland study found that wombats with mange are more likely to be observed during daylight hours than healthy wombats. A possible reason for this change in behaviour is likely to be that mange-infected wombats have a higher energy requirement necessitating the continuous search for food. The increased daylight activity by mange-infected wombats may also be related to the vision impairment of severely mange-infected wombats. Whatever the cause of this behavioural change, it is possible to get a misleading impression of mange prevalence from daylight observations.
How can mange be treated?
Individual wombats and other animals can be treated for mange. While this may be relatively straight forward for tame or captive animals, it is more challenging to treat animals in the wild, especially for wombats which are typically nocturnal, live underground and are not well suited to captivity.
Effective treatment of mange in wombats requires weekly doses of moxidectin (Cydectin) for eight weeks followed by four fortnightly doses. Recommended treatment methods are delivery of the acaricides (pesticides that kill mites and ticks) via a burrow flap over a wombat burrow that doses the wombat as it enters and exits the burrow, or by direct application straight onto the wombat via a scoop on a pole. The pole and scoop method is generally used for badly affected wombats that can be easily approached. Wombats should not be chased to apply treatment.
Two studies of the effectiveness of treating mange in common wombats using the burrow flap method have been conducted in the wild, one in Tasmania and one in NSW. Results indicate that the effectiveness of the treatment regime is variable at the population level. Both studies highlighted the considerable logistical challenges in treating all individuals and all burrows.
Reinfection of treated wombats can occur if infected wombats remain in the population, if other hosts transmit mites to wombats, or if mites remain viable and infectious in the landscape. Due to the potential for the mites to develop resistance to the acaricides continuous treatment is not encouraged.
Why such long treatment regimes?
Multiple doses of Cydectin are required, as the drug isn’t easily absorbed through affected skin and therapeutic drug levels need to be maintained for long enough for the skin condition to improve and the animal to resist re-infection from the environment.
Wombat exiting burrow fitted with a burrow flap
copyright: A. Martin
Should wombats be treated in captivity or in the wild?
Wherever possible wombats should be treated for mange in the wild. Holding a wild wombat in captivity comes at some risk to the wombat due to stress associated with capture, handling and confinement. This stress is exacerbated in mange affected wombats whose immune systems are already compromised.
The survival of captive-raised or captive-held wombats post-release is poorly known and evidence from a limited number of captive-release studies on other animals suggests that survival may be poor. In some circumstances, bringing wombats into captivity to treat mange may be appropriate provided suitable facilities are available and they are located within the areas animals have been sourced and that they will be released in similar areas.
Does mange occur in other species?
Mange has been reported in over 100 species of mammal, including humans. The disease is referred to as scabies in humans and mange in other species. The broad range of hosts for sarcoptic mange includes domestic dogs, livestock (e.g. cattle, pigs, goats, camels) and wildlife (e.g. red foxes, coyotes, wolves, deer, bobcats, wombats, koalas and wallabies).
Why don’t wallabies get mange as badly?
Mange has been recorded in some species of wallabies. Wallabies do not get exposed to the mites that cause mange as often as wombats because of their different social behavior and resting places. Wombat burrows are believed to be good places for the mites to survive and for transmission between wombats.
Can Tasmanian Devils contract mange?
Mange due to Sarcoptes scabiei has not been recorded in Tasmanian devils. Sarcoptes scabiei mites can infect a range of different mammalian hosts, with clinical severity varying among species. Wombats, dogs and foxes are particularly susceptible to developing mange symptoms, especially if they have a weakened immune system that makes them more vulnerable to infections. Devils sometimes show mild symptoms of mange, but the causal agent is a devil-specific mite, Satanicoptes armatus, not Sarcoptes scabiei.
What problems do wombats cause for landholders?
The main concern landholders raise about wombats is the damage they can cause to fences, especially wallaby proof fences, allowing wallabies to damage pastures and crops. Wombats can cause significant pasture loss, damage to dam walls and other infrastructure, and their burrows can be a hazard for livestock, as well as horse and motorbike riders
How can landholders deal with wombats impacting their properties?
Landholders are encouraged to adopt non-lethal approaches to managing impacts of wombats on their properties such as installing wombat gates to allow wombats, but not wallabies, to enter and exit pasture areas. However, DPIPWE recognises that these approaches are not always possible or successful in managing the impacts.
Wombats are a protected wildlife species and a permit is required to use lethal methods. Applications for a permit to take wombats are assessed on a case by case basis, which includes a visit to the applicant’s property. A range of factors are taken into account including: the local abundance of wombats, the impacts that the wombats may be having on the property, and whether or not non-lethal measures will be effective at the site. If a permit is issued, it will specify the number of wombats that are authorised to be taken and the timeframe during which the permit applies.
There is currently a moratorium on the issuing of crop protection permits in the West Tamar region.
What happened to the wombats at Narawntapu National Park?
Wombats were previously a common species in Narawntapu National Park in northern Tasmania. Although mange has been present in the park for decades, there was an outbreak of mange in 2006 following a severe drought. Since then mange has resulted in a substantial reduction in wombat numbers. Monitoring by the University of Tasmania between 2010 and 2016 shows that the wombat population declined by 94%.
What was done to help the wombats in the Narawntapu National Park?
The University of Tasmania, with assistance from the Parks and Wildlife Service, undertook an experiment to evaluate if mange could be eliminated from the wombat population that remained in the western end of Narawntapu National Park.
This involved attempting to treat the entire wombat population with burrow flaps and Cydectin. This was a labour intensive program that involved deploying and maintaining >200 burrow flaps on all known wombat burrows that were active.
Although, the program was temporarily successful in treating some individuals in the population, it failed to treat all wombats and thus eliminate the disease. This research showed that it is very difficult to ensure that all wombat burrows and burrow entrances are found and that all wombats will receive the full treatment regime. While treating individual wombats can be successful, treating whole populations is very difficult.
Further research is underway to try and improve the future for wombats at Narawntapu, and capacity to control mange disease in wombat populations more generally.
Will Narawntapu National Park ever have wombats again?
A small number of wombats still occur in Narawntapu National Park. It is not known how long it will take for the population to recover. There is potential for wombats to self-introduce from surrounding areas but active re-introduction is also a possibility. A plan is being developed by DPIPWE to consider a range of options and triggers for management to facilitate the return of wombats to the park.
If a new wombat population establishes in Narawntapu National Park will it be re-infested with mange?
As mites live on a range of host species, there can be no guarantees that a new wombat population won’t be re-infested.
Is mange the only factor that impacts on wombats in Tasmania?
No, whilst mange is the most significant factor affecting their health, there are other factors that impact wombats. Like a range of native animal species, wombats are susceptible to roadkill. Drivers can play an important role in reducing this threat by being aware of wildlife hotspots and reducing speed at key times between dusk and dawn.
Uncontrolled dogs can also impact on wombats which is why it is important to ensure that dogs remain under effective control and are not allowed to roam unsupervised.
How can I help?
There are many ways you can help:
- Report observations of injured wombats or wombats with mange to DPIPWE by calling 03 61654305 or via email email@example.com;
- Treat mange-infected wombats in your area – contact DPIPWE;
- Drive carefully in “wombat country” to reduce the number of wombats killed or injured by cars;
- Use non-lethal methods to manage wombats on agricultural land, including “wombat gates” to allow their passage through fences; and
- Prevent dogs from roaming in areas where wombats occur
What do I do if I see a mange-infected wombat?
Use the DPIPWE Wildlife Management Branch contact details at the bottom of the page to provide details of the location and condition of the individual.
Photographs are very useful for assessment of the condition of the wombats.
Do I need permits to treat mange infected wombats in Tasmania?
Yes, permits are required to treat mange in wombats, both in the wild and in captivity.
Mange Management Inc.
in Victoria have been issued with a Minor Use Permit for the use of Cydectin to treat mange in wombats by the Australian Pesticides and Veterinary Medicine Authority (APVMA). The permit allows them to act as an umbrella group to oversee the use of this chemical (currently classified as ‘off-label’ for use on wombats) by other groups in all states of Australia.
Any groups in Tasmania wishing to treat wombats with Cydectin must apply to be covered by this permit. A copy of the application form, as well as a copy of the APVMA permit are available on our website
Without this sub permit wombats cannot be treated with Cydectin.
Additionally, those groups wanting to use the ‘pole and scoop’ method of application must apply for a ‘Permit to Take – for the purpose of pursuing’ from DPIPWE.
A person may apply on behalf of the group, however all members must provide their details.
Please note that an APVMA sub permit is a requirement for DPIPWE to issue this permit.
Without this permit wombats cannot be treated with pole and scoop, as it is an offence to ‘pursue’ a wombat under the Nature Conservation Act 2002.
Information sources and further reading
Borchard, P., Eldrigde, DJ and IA Wright, 2012 ‘Sarcoptes mange (Sarcoptes scabiei) increases diurnal activity of bare-nosed wombats (Vombatus ursinus) in an agricultural riparian environment’ Mammalian Biology 77, 244-248
Fraser, TA., Charleston, M., Martin, A., Polkinghorne, A. and S. Carver, 2016, ‘The emergence of sarcoptic mange in Australian wildlife: an unresolved debate. Parasite and Vectors 9:316. DOI 10.1186/s13071-016-1578-2
Gray DF, 1937, ‘Sarcoptic mange affecting wild fauna in New South Wales’ Aust Vet J 13: 154-155
Martin, RW, Handasyde, KA and LF Skerratt, 1998, ‘Current distribution of sarcoptic mange in wombats.’ Aust Vet J, 76(6): 411-414
Simpson, K., Johnson, CN and S. Carver, 2016, ‘Sarcoptes scabiei: The mange mite with mighty effects on the common wombat (Vombatus ursinus). PLoS ONE 11(3): e0149749
Skerratt, LF, 2003, ‘Clinical response of captive common wombats (Vombatus ursinus) infected with Sarcoptes scabiei var. wombati.’ J Wildl Dis 39 (1): 179-192
Skerratt, LF, 2005, ‘Sarcoptes scabei: an important exotic pathogen of wombats’ Microbiology Australia 26: 79-81
Skerratt, LF, Martin, RW and KA Handasyde, 1998, ‘Sarcoptic mange in wombats’, Aust Vet J, vol 76, no. 6, pp 408-410
Skerrat, LF, Skerrat, JH, Banks, S, Martin, R and KA Handasyde, 2004, ‘Aspects of the ecology of common wombats (Vombatus ursinus)’, Australian Journal of Zoology, vol. 52 no. 3, pp. 303-330