Geographic Range
Currently
Sarcophilus laniarius
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.
- Biogeographic Regions
- australian
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.
- Habitat Regions
- temperate
- terrestrial
- Terrestrial Biomes
- savanna or grassland
- forest
- rainforest
- scrub forest
- Aquatic Biomes
- coastal
- Other Habitat Features
- agricultural
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.
- Other Physical Features
- endothermic
- homoiothermic
- bilateral symmetry
- Sexual Dimorphism
- male larger
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.
- Mating System
- polygynandrous (promiscuous)
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.
- Key Reproductive Features
- iteroparous
- seasonal breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- viviparous
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.
- Parental Investment
- altricial
-
pre-fertilization
- provisioning
-
protecting
- female
-
pre-hatching/birth
-
provisioning
- female
-
protecting
- female
-
provisioning
-
pre-weaning/fledging
-
provisioning
- female
-
protecting
- female
-
provisioning
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.
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.
Home Range
Tasmanian devils stay within a relatively small home range, traveling an average of
3.2 km in a night.
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.
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.
- 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. laniarius
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).
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.
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.
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.
Other Comments
Tasmanian devils were previously known by the name
Sarcophilus laniarius.
Additional Links
Contributors
Tanya Dewey (author, editor), Animal Diversity Web.
Bridget Fahey (author), University of Michigan-Ann Arbor, Almaz Kinder (author), University of Michigan-Ann Arbor.
- Australian
-
Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- 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.
- forest
-
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
- 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.
- scrub forest
-
scrub forests develop in areas that experience dry seasons.
- coastal
-
the nearshore aquatic habitats near a coast, or shoreline.
- agricultural
-
living in landscapes dominated by human agriculture.
- 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.
- 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.
- polygynandrous
-
the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.
- 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).
- seasonal breeding
-
breeding is confined to a particular season
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- viviparous
-
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
- 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.
- nocturnal
-
active during the night
- motile
-
having the capacity to move from one place to another.
- sedentary
-
remains in the same area
- solitary
-
lives alone
- visual
-
uses sight to communicate
- acoustic
-
uses sound to communicate
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- acoustic
-
uses sound to communicate
- chemical
-
uses smells or other chemicals to communicate
- carrion
-
flesh of dead animals.
- carnivore
-
an animal that mainly eats meat
- scavenger
-
an animal that mainly eats dead animals
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/ .