Tasmanian devil (Sarcophilus harrisii)
|French:||Diable De Tasmanie|
|Size||Head-body length: 52.5 - 80 cm (2)|
Tail length: 23 - 30 cm (2)
Max weight: 18 kg (3)
The Tasmanian devil is classified as Endangered (EN) on the IUCN Red List (1).
Haunted by its chilling nocturnal screeches, it was the early European settlers that gave the Tasmanian devil (Sarcophilus harrisii) its alarming name (3) (4) (5). The largest of the carnivorous marsupials, it is robustly built, with a broad head that supports powerful jaws and strong teeth capable of crushing all but the largest bones (3) (4) (5) (6). The hindquarters slope down in a manner reminiscent of its larger African counterpart, the hyaena (5), while its tail is short and thick (3) (4). The coarse fur is mostly black, but there are often distinctive white markings across the chest, shoulders and rump (3) (4).
Although the Tasmanian devil is now only found in Tasmania, historically it occupied much of the Australian mainland, but disappeared around 400 years ago following the introduction of the dingo by Aboriginal people (1) (2) (3) (4).
Found in all of Tasmania’s major habitats, from the coast to the mountains, but particularly in dry eucalypt forests, open woodland, and agricultural areas (1) (3) (4) (6).
Despite the Tasmanian devil’s fierce reputation, in reality, it has a rather shy, cautious disposition (2) (4). Only when threatened, or in competition with other devils for food, does it resort to aggressive behaviour, but even this is usually limited to a theatrical display of growls, snarls, and screeches, rather than physical clashes (2) (3) (4) (6). Sheltering by day in dense bush or a den such as an underground burrow or a hollow log, the Tasmanian devil emerges at night to search for food. It has a slightly clumsy, loping gait, but can cover considerable ground (up to 16 kilometres) in a single night (1) (2) (3). While capable of hunting small prey, scavenging is its forte, with an acute sense of smell enabling it to rapidly locate dead animals in the bush (3) (4) (6). Typically it will wholly devour whatever meat is available, from insects to beached fish, with small mammals such as possums, wombats and wallabies being particular favourites (2) (3) (4). It is not uncommon for several devils to arrive at one carcass at the same time, precipitating the noisy displays of aggression necessary to establish a hierarchy of dominance (3) (4) (6).
The Tasmanian devil is a solitary animal, but at times is also highly social, such as when feeding communally, or during the breeding season (4) (5). Mating usually occurs between the months of January and March, but if a female doesn’t fall pregnant or loses young, she can come into oestrus again and mate up until July (3) (4). The female exhibits little in the way of fidelity, visiting several males in quick succession, whilst each male, uncertain of their own paternity, will try to physically prevent the promiscuous female from leaving (5). After a three week gestation period, the female gives birth to up to 20 young but as the female only has four teats, the first four young that make it to the pouch immediately attach to one of the teats in the backward-opening pouch. At around five months old, the fully-furred young emerge from the pouch and take up residence in a simple, grass-lined den. Another month on, and they start to explore the den’s surroundings, eventually becoming fully weaned and independent at about ten months old (2) (3) (4). Sexual maturity is reached towards the end of the second year, with an average life expectancy of around five to six years in the wild (1) (2) (3).
Historically, early European settlers considered the Tasmanian devil a nuisance that raided poultry coops and killed valuable livestock (1) (2) (3). As a consequence, this iconic species was persecuted for many years through trapping and poisoning (1) (3). In the face of persecution, deforestation, and a severe epidemic in the early 20thcentury, the Tasmanian devil became extremely rare, until a protective law was passed in 1941 that saw its numbers gradually rise again (3). Although systematic poisoning resumed with questionable merit in the 1980s and 1990s, by this stage the population had recovered sufficiently for the species to be abundant in many parts of Tasmania (2). Then in the mid 1990s, disaster struck when a number of Tasmanian devils were sighted with strange facial tumours, later discovered to be a fatal cancer now commonly known as Devil Facial Tumour Disease (DFTD) (3) (4) (5).
Since its discovery, DFTD has had a colossal impact on the Tasmanian devil population, with overall sightings of devils on annual spotlight surveys declining by 80 percent. (4). Untreatable, highly infectious, and consistently fatal, DFTD presents by far the biggest threat to the species’ survival (1) (3) (4). The disease is now present over 60 percent of the Tasmanian devil’s range, with the proportion of infected adults in some areas reaching as high as 83 percent (1) (3). Owing to low genetic diversity in the population as a whole, resistance to the disease, which spreads through biting, has not yet been discovered in any one population or individual (1) (3) (7) (8).
Aside from DFTD, the Tasmanian devil also faces the uncertain threat of competition with the introduced red fox (Vulpes vulpes), which shares its preferences for den sites, habitat and food (1) (3). While in the past fox numbers have been maintained at low levels, there is concern that the current decline in the Tasmanian devil population, brought about by DFTD, is allowing fox numbers to increase, which in turn will have a secondary negative impact on the devil population (1). Further compounding the plight of this luckless species is the high frequency at which it ends up as road-kill, and its continued persecution as a pest by farmers (1) (4).
In the absence of drastic conservation measures, the Tasmanian devil is projected to be extinct in the wild within 25 years (3). Fortunately, considerable effort is being made at the local, national, and international level to prevent the realisation of this dire forecast. In May 2009, Australia’s Federal Government uplisted the Tasmanian devil to the ‘Endangered’ category under the Commonwealth’s Environment Protection and Biodiversity Conservation Act 1999, which will ensure the species receives greater protection under national environmental laws (3) (4). At the forefront of conservation efforts is the Save the Tasmanian Devil Program, launched in 2003 and co-ordinated by the Tasmanian Government’s Department of Primary Industries and Water (1) (3) (4). The focus of the program is: to continue to monitor the impact of DFTD on the Tasmanian devil population; to further investigate the disease, including its transmission and causes; to develop methods of managing the impact of the disease; and to maintain an insurance population recruited from disease free areas. Should the need arise, this captive bred insurance population could prove critical to establishing a healthy wild population in the wake of DFTDs devastating impact (3) (4).
Find out more about the conservation of the Tasmanian devil:
Save the Tasmanian Devil:
Tasmania Department of Primary Industries and Water:
Authenticated (15/09/2010) by Dr Samantha Fox, Save the Tasmanian Devil Program, Hobart, Australia.
- Gestation: the state of being pregnant; the period from conception to birth.
- Marsupials: a diverse group of mammals characterised by their reproduction, in which gestation is very short, and the female typically has a pouch (marsupium) in which the young are raised. When born, the tiny young crawls to the mother’s teats, where it attaches and stays for a variable amount of time, whilst it continues to develop. Marsupials also differ from placental mammals in their dentition.
- Oestrus: the time of ovulation (release of an egg from the ovary) in female mammals, when the female becomes receptive to males, also known as ‘heat’.
IUCN Red List (May, 2009)
- Nowak, R.M. (1999) Walker's Mammals of the World. Johns Hopkins University Press, Baltimore, Maryland.
Tasmania Department of Primary Industries and Water (May, 2009)
Save the Tasmanian Devil (May, 2009)
- Macdonald, D. (2001) The New Encyclopedia of Mammals. Oxford University Press, Oxford.
- Burnie, D. (2001) Animal. Dorling Kindersley, London.
- Siddle, H.V., Kreiss, A., Eldridge, M.D.B., Noonan, E., Clarke, C.J., Pyecroft, S., Woods, G.M. and Belov, K. (2007) Transmission of a fatal clonal tumor by biting occurs due to depleted MHC diversity in a threatened carnivorous marsupial. Proc Natl Acad Sci USA, 104: 16221-16226.
- McCallum, H. (2008) Tasmanian devil facial tumour disease: lessons for conservation biology. Trends in Ecology and Evolution, 23(11): 631-637.