Sarcophilus harrisiiTasmanian devil

Geographic Range

Currently Sarcophilus harrisii is found only in Tasmania, although fossil evidence suggests that it once occupied much of the Australian mainland. It has been suggested that its absence in many previously occupied areas can be explained by competition with the introduced dingo in Australia. (Nowak, 1991)

Habitat

Tasmanian devils are numerous throughout Tasmania except in areas where there has been extensive habitat fragmentation and deforestation. They are most numerous in coastal heath and rangeland areas where agricultural practices maintain a constant supply of carrion. They also occur in open, dry schlerophyll forest and mixed schlerophyll rainforest. Their dens typically are located in hollow logs, caves, or burrows. (DPIWE, Nature Conservation Branch, 2005; Nowak, 1991)

Physical Description

Tasmanian devils are stocky with a brownish black pelage. They have a white throat patch, white spots on their sides and backside, and a pinkish snout. The head is massive with well developed jaw muscles. Molar teeth are heavy and adapted for their role in crushing bone and tearing through muscle and thick skin. Females are slightly smaller than males. Body size varies considerably with diet, habitat, and age. Large males may reach 12 kg and 30 cm at the shoulder. Total length ranges from 525 to 800 mm and tail length from 230-300 mm. Male weight ranges from 5.5 to 12 kg and female weight from 4.1 to 8.1 kg. Fat storage occurs in the tail, as in many dasyurids. Females have four mammae and, unlike many other dasyurids, the marsupial pouch is completely closed when breeding. (DPIWE, Nature Conservation Branch, 2005; Nowak, 1991)

  • Sexual Dimorphism
  • male larger
  • Range mass
    4 to 12 kg
    8.81 to 26.43 lb
  • Range length
    525 to 800 mm
    20.67 to 31.50 in

Reproduction

Males compete for access to breeding females. Females are only temporarily subdued by a male for mating, there is no longer term association of males and females. (DPIWE, Nature Conservation Branch, 2005)

Tasmanian devils are monestrous. Most mating takes place in March and the young are born in April after a gestation period of 21 days. Litter size is usually 2-3, although 4 mammae are available and 4 young are possible. The young then travel to the pouch where they remain for 4 months. By 5-6 months old the young are completely weaned, becoming independent in December. Females become sexually mature at two years old. (DPIWE, Nature Conservation Branch, 2005; Nowak, 1991)

  • Breeding interval
    Tasmanian devils breed once yearly.
  • Breeding season
    Tasmanian devils breed in April.
  • Range number of offspring
    4 (high)
  • Average number of offspring
    2-3
  • Average gestation period
    21 days
  • Range weaning age
    5 to 6 months
  • Average time to independence
    8 months
  • Average age at sexual or reproductive maturity (female)
    2 years

Females nurse and protect their offspring in their pouch during most of their development. After weaning the young begin to disperse from their natal range. (DPIWE, Nature Conservation Branch, 2005; Nowak, 1991)

  • Parental Investment
  • altricial
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female

Lifespan/Longevity

Tasmanian devils most often live to a maximum of 5 years old in the wild. Most young die immediately after dispersing out of their natal range as a result of food scarcity or competition. They may live 7 to 8 years. (DPIWE, Nature Conservation Branch, 2005; Nowak, 1991)

Behavior

Tasmanian devils are nocturnal and usually solitary. Occasionally, when individuals congregate at food sources, such as carrion, they interact aggressively but they are not territorial. When fighting, Tasmanian devils vocalize with growls, screeches, and vibratos. There also seems to be a learned dominance hierarchy, at least in captive situations.

Both males and females make nests of bark, grass and leaves which they inhabit throughout the day. They may be seen sunbathing during the day in quiet areas. (DPIWE, Nature Conservation Branch, 2005; Nowak, 1991)

Home Range

Tasmanian devils stay within a relatively small home range, traveling an average of 3.2 km in a night. (Nowak, 1991)

Communication and Perception

Tasmanian devils have keen senses of smell, sight, touch, and taste. They communicate through a wide variety of vocalizations and physical cues, such as yawning and raising their tails. Tasmanian devils are regarded with some awe because of the blood-curdling shrieks and growls they use, particularly when a group is scavenging a carcass. (DPIWE, Nature Conservation Branch, 2005)

Food Habits

Tasmanian devils have been considered livestock predators. In reality, these marsupials take most of their large prey, such as wombats, wallabies, sheep, and rabbits, in the form of carrion. Tasmanian devils are efficient scavengers, eating even bones and fur. Tasmanian devils may have depended on carrion left from Tasmanian wolf kills in historical times. Other food items, such as insects, insect larvae, snakes, and small amounts of vegetation, are taken when encountered. Tasmanian devils forage in a slow, lumbering manner, using their sense of smell to find food at night. They are famous for their rowdy communal feeding, which is accompanied by aggression and loud vocalizations. (DPIWE, Nature Conservation Branch, 2005; Nowak, 1991; DPIWE, Nature Conservation Branch, 2005; Nowak, 1991)

  • Animal Foods
  • mammals
  • amphibians
  • reptiles
  • carrion
  • insects
  • terrestrial non-insect arthropods
  • Plant Foods
  • roots and tubers
  • fruit

Predation

Adult Tasmanian devils have few natural predators, although Tasmanian wolves may have preyed on them occasionally. Small S. harrisii may fall prey to eagles (Accipitridae), owls (Strigiformes), and spotted tail quolls (Dasyurus maculatus). Tasmanian devils are ferocious when attacked and are impressively armed with heavy jaw musculature and robust teeth, they are able to protect themselves against larger predators. Their nocturnal activity may help them avoid some predators (such as Tasmanian wolves, historically). (DPIWE, Nature Conservation Branch, 2005)

Ecosystem Roles

Tasmanian devils are important predators in native, Tasmanian ecosystems. After the Tasmanian wolf (Thylacinus cynocephalus), they are the largest native, mammalian predator on Tasmania.

Economic Importance for Humans: Positive

Tasmanian devils are important as top predators in native, Tasmanian habitats. As scavengers they are important in removing carcasses. (DPIWE, Nature Conservation Branch, 2005; Nowak, 1991)

Economic Importance for Humans: Negative

Tasmanian devils were once thought to kill livestock, such as sheep. Although this is unlikely, they have been known to kill poultry. They may be considered "nuisance" animals by some. However, the value of Tasmanian devils as important members of functioning ecosystems and as scavengers probably outweighs any negative effect of these animals on human. (DPIWE, Nature Conservation Branch, 2005; Nowak, 1991)

Conservation Status

At one time, Tasmanian devils were thought to be in danger of extinction due to persecution by settlers and destruction of forest habitat. Populations stabilized, and may have increased with the increased availability of carrion in rangelands. In recent years many populations of Tasmanian devil have been devastated by a new, usually lethal, cancer-like disease that is spreading rapidly throughout Tasmania. There is some evidence that this disease is not new, but is endemic to Tasmanian devils. Historical record and epidemiological modeling suggest that this epidemic may cycle through Tasmanian devil populations at 77-146 year intervals. Although this has no resulted in extinction in the past, the effect of additional, human-associated threats may pose a grave threat to the persistence of Tasmanian devil populations. Tasmanian devils are protected in Tasmania. (Bradshaw and Brook, 2005; DPIWE, Nature Conservation Branch, 2005; Nowak, 1991)

Other Comments

Tasmanian devils were previously known by the name Sarcophilus laniarius. (Nowak, 1991; Wilson and Reeder, 1993)

Contributors

Tanya Dewey (author, editor), Animal Diversity Web.

Bridget Fahey (author), University of Michigan-Ann Arbor, Almaz Kinder (author), University of Michigan-Ann Arbor.

Glossary

Australian

Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.

World Map

acoustic

uses sound to communicate

agricultural

living in landscapes dominated by human agriculture.

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

carnivore

an animal that mainly eats meat

carrion

flesh of dead animals.

chemical

uses smells or other chemicals to communicate

coastal

the nearshore aquatic habitats near a coast, or shoreline.

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

polygynandrous

the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

scavenger

an animal that mainly eats dead animals

scrub forest

scrub forests develop in areas that experience dry seasons.

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

solitary

lives alone

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

References

Bradshaw, C., B. Brook. 2005. Disease and the devil: density-dependent epidemiological processes explain historical population fluctuations in the Tasmanian devil. Ecography, 28: 181-190.

DPIWE, Nature Conservation Branch, 2005. "Tasmanian Devil Facial Tumour Disease" (On-line). Department of Parks, Industries, Water, and Environment, Tasmania. Accessed June 24, 2005 at http://www.dpiwe.tas.gov.au/inter.nsf/WebPages/JCOK-65X2Y6?open.

Nowak, R. 1991. Walker's Mammals of the World. Baltimore: The Johns Hopkins University Press.

Wilson, D., D. Reeder. 1993. "Mammal Species of the World" (On-line). Accessed 24 May 2001 at http://www.nmnh.si.edu/msw/.