Tasmanian Devil

The Tasmanian devil acquires its unique name from its sole native habitat, the island state of Tasmania in Australia. The scientific name of the Tasmanian devil animal is Sarcophilus harrisii and belongs to the family Dasyuridae. The Tasmanian devil, in recent years, has also been reintroduced to mainland Australia’s New South Wales with a small breeding population. The defining characteristics of the predatory land mammal include its black fur, muscular and stocky build and pungent odour, combined with large noises they produce, hence the name devil. 

In this article, we will discuss the marsupial in great lengths including the Tasmanian devil appearance, habitat, reproduction, behaviour and more.

Classification 

• Kingdom: Animalia

• Phylum: Chordata

• Class: Mammalia

• Order: Dasyuromorphia

• Family: Dasyuridae

• Genus: Sarcophilus

• Species: Sarcophilus harrisii

Tasmanian Devil Appearance and Characteristics

Among the surviving carnivorous marsupials, the Tasmanian devil is the largest with its giant head, tail almost half the size of the length of its body and a thick, squat build. Characteristically, the forelegs of the Tasmanian devil are somewhat longer as compared to the hind legs, something which is unlike marsupials. This allows them to run at about 13 kmph for shorter distances. The fur of the Tasmanian devil is generally back interspersed with irregular white patches on the rump and the chest. 

Sexual dimorphism is observed with males being larger than females. The average bodyweight of the males is 8 kg, head and body length of about 652 mm and a tail length of 258 mm. The average bodyweight of the females is 6 kg, the head and body length about 570 mm and the tail length of 244 mm. 

The forefeet of the Tasmanian devils bear five long toes, one from the side and the other four, pointing towards the front. This gives the animals the ability to hold their food. Their hind feet bear four toes. The claws of the Tasmanian devils are non-retractable. The baby Tasmanian devils grow fully by the time they attain two years of age. The lifespan of the Tasmanian devils is usually around 5 years. The only known Tasmanian devil to live up to seven years of age was a male named Coolah, which was raised in captivity. 

The centre of mass of the Tasmanian devil is relatively low. They have fat tails in which they store their body fat. For most parts, the tail is non-prehensile and plays an important part in the locomotion, social behaviour and physiology of the animal. The tail provides a counterbalance to assist in stability when the animal moves quickly. The tail is also used in the marking of the ground behind the devil with a strong, pungent, anogenital scent present at the tail’s base. 

The genitalia in the males are external, contained in a pouch-like structure formed by the abdomen’s lateral ventrocrural folds. This helps in partially hiding and protecting the male testes. In females, the pouch containing the genitalia opens backwards, which is not usually seen in Tasmanian native animals. 

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The face of the Tasmanian devil bears long whiskers while the head has clumps on top. The whiskers in the devils can extend from the chin’s tip to as far as the rear of the jaw spanning the shoulder. These features help the animal in prey location when they forage in the dark along with helping them to detect if other devils are nearby when they are feeding. 

The dominant sense in the Tasmanian devils is hearing but their sense of smell is also excellent with a range of about 1 kilometre. Given the marsupials are primarily nocturnal and hunt during the night, their strongest vision is in black and white where they can readily detect moving objects. They, however, experience difficulty when it comes to seeing stationary objects. 

Among the living mammalian carnivores, the bit of the Tasmanian devil is the most powerful relative to its body size. The extensive opening of the jaw facilitates a larger amount of power generation, strong enough to tear the meat and crush the bones of its prey. The comparatively large head of the Tasmanian devil accounts in part for the power in its jaws. The cheek teeth and canines of the devil are prominent like all the members of the family. They bear four pairs of upper incisors and three pairs of lower incisors. The long claws of the Tasmanian devil allow for digging of burrows and easy seeking of subterranean food along with allowing to grip prey or mating strongly. 

Tasmanian Devil - Habitat and Distribution

In their native region of the island of Tasmania, devils are found there across all types of habitats. They are distributed throughout the mainland of Tasmania, even on the outskirts of the urban areas as well as on Robbins island, which during low tide is connected to the Tasmanian mainland. The north-western population of the Tasmanian devils are present west of the Forth River extending far south up to the Macquarie Heads.

The ideal habitat of the Tasmanian devils is within the north-western and eastern Tasmania, where the annual rainfall is low to moderate. They are known to prefer coastal woodlands and dry sclerophyll forests, where their population is high. They also favour open, dry forests rather than tall, wet forests. 

Tasmanian Devil Behaviour

In the ecosystem of Tasmania, the devil is regarded as a keystone species. The Tasmanian devils are crepuscular and nocturnal hunters and they spend their days in a hole or dense bush. The young devils are capable of climbing trees but with age, they grow larger and this becomes difficult. They are capable of swimming as well. The animals are not found in packs and once weaned, they spend most of their time alone. In a region, all the devils are part of a common social network. 

Although generally non-territorial, the female Tasmanian devils display such behaviour around their dens. Instead, the devils are known to occupy a home range. Their home ranges are estimated to vary from 4 to 27 sq. km within a period of 2 to 4 weeks. The geometry and location of these ranges are influenced by the distribution of food, pademelons and wallabies, in particular. 

On a daily basis, the Tasmanian devils use three to four dens. Wombat-owned dens are preferred as maternity dens given their security. Alternatively, thick grass tussocks, caves and dense vegetation beside creeks are used as dense as well. Adult devils are known to make use of the same dens for life. Except for young devils that live with their mother in the den, all the other Tasmanian devils are mobile, which change dens within 1 to 3 days. Such devils mainly travel through saddles, lowlands and banks of creeks and they prefer paths taken by livestock and the tracks carved out in the rocky terrain and eschewing steep slopes. Males usually spend more time eating as they need more food and thus, they travel less. Devils are known to steal blankets, pillows and clothes in the areas near human habitation. 

Diet of Tasmanian Devils

Rather than hunting live prey, Tasmanian devils are more opportunistic and often eat carrion. Their favourite prey is the wombat because of the fact that they have a high-fat content and can be hunted down easily. The devil is also known to eat small native mammals like the potoroos, bettong and wallabies along with domestic mammals such as rabbits and sheep. In addition to this, they also feed on birds, fruit, vegetable matter, fish, insects, frogs, tadpoles and reptiles. Their diet is mainly dependent on the food available and is thus, widely varied. They have also been known to forage corpses by digging. 

The Tasmanian devils eat about 15 percent of their body weight on average. However, if the opportunity arises, they can consume up to 40 percent of their body weight in as little as 30 minutes. They can eliminate the carcass of smaller animals in their entirety and even consume the fur along with the bones if they desire. This behaviour of the Tasmanian devils helps in preventing the spread of insects.

The juvenile Tasmanian devils that are able to climb trees consume birds’ eggs and grubs in addition to the small invertebrates and vertebrates. They have been seen to capture birds as well. 

Hunting Behaviour 

The Tasmanian devil, National Geographic says, hunts alone. The eating process, however, is a social event among the devils. This behaviour of the devils makes them unique among the carnivores. Their raucous communal eating is also known to generate a substantial amount of noise, which can be heard kilometres away. The noise generated is related to the carcass’ size. Groups of 2 to 5 are usually seen but up to 12 individuals can also gather for communal eating. 

The Tasmanian devils are known to digest their food very fast. Their defecation process, much like their eating habits, is also communal and they are known to return to the same places to defecate in what is called a devil latrine. 

Reproduction in Tasmanian Devils

Sexual maturity in females is typically reached in the second year, which is when they start breeding. They become fertile annually generating multiple ova while they are in the heat. The reproductive cycle of the Tasmanian devil starts in March or April when there is an abundance of prey. This is so that the finishing of the weaning period coincides with the availability of maximum food supplies for the newly born devils roaming in the wild. 

The mating occurs both during day and night in sheltered locations in the month of March. Males are known to engage in physical conflict with other males for mating preferences as the female mates with the dominant male in an attempt to select the best offspring genetically. In 21 days, females can ovulate a maximum of three times and engage in copulation which can take 5 days. Tasmanian devils are not monogamous and females, if not guarded after mating, will copulate with several males. Likewise, during a breeding season, males also reproduce with several females. 

Over the course of their lifetime, male Tasmanian devils are capable of producing up to 16 offspring. The Tasmanian devil gestation period is 21 days after which 20 to 30 young devils are birthed. The females give birth standing up. Each of the young devils weighs between 0.18 and 0.24 grams approximately. The front limb of the young ones has well-developed digits with the presence of claws that are not deciduous. The body is pink in colour and the eyes are spots. External ears or openings are not seen. The sex of the Tasmanian devils can usually be determined at birth, as an external scrotum is present. 

The young ones of the Tasmanian devils are called imps, joeys or pups. Around 60 percent of the young ones do not survive until maturity given the large litter that remains inside the pouch after birth and only four nipples of the mother available for nursing. More female young ones are seen surviving than males. 

The young devils that obtain nourishment inside the pouch develop quickly. The rhinarium becomes heavily pigmented in the second week making it distinctive. The external ear parts become visible at around 15 days and while they remain attached to the head, they open only when the young devil is around 10 weeks in age. The blackening of the ear starts after around 40 days when it is less than a centimetre long and attains a length of 1.2 - 1.6 cm when it is erect. At 16 days, the eyelids become apparent, while the whiskers and the lips show at 17 and 20 days respectively. Eyelids, though formed, cannot open until 3 months. The lips open after 10 to 11 weeks prior to which, the young devils can make squeaking noises when they are 8 weeks old. The young ones which were pink in colour until this time, show fur growth at about 49 days and develop a full coat by 90 days. After the development of the fur coat, the eyes open between 87 - 93 days. The young devils leave the pouch 105 days after birth when they weigh around 200 gms. 

The young devils after leaving the pouch remain inside the den for a period of another three months. They first start to venture out of the den in the months of October to December. They become completely independent in the month of January. The young ones during this phase of transition are generally accompanied and are thus kept safe from predation. The young ones continue to feed on their mother’s milk during this period. 

Tasmanian Devil - Fun Facts

• The teeth of the Tasmanian devil never stop growing.

• When confronted, the devils are known to yawn.

• At the time of birth, a devil pup is the size of a rice grain

• The devil's use the bodies of their prey to sleep

So, in this article, we have attempted to learn about the Tasmanian devil to great lengths. The Tasmanian devil, with all its quirks, is a unique animal indeed.