Friday, 12 December 2008
Endangered Tasmanian Devils Headed to Extinction
The Tasmanian Devil, at one time, covered all of Australia. The size of a small dog, but stocky and muscular, the Tasmanian Devil is now the largest carnivorous marsupial in the world after the extinction of the Thylacine in 1936. It is characterized by its black fur, offensive odour when stressed, extremely loud and disturbing screech, and ferocity when feeding. It is known to both hunt prey and scavenge carrion and although it is usually solitary, it sometimes eats with other devils. Now the animal is limited to the southwest of Tasmania in an endangered status because the farmers saw it as a threat to their livestock and poultry. It was exterminated in Australia from the bounty placed upon it by farmers, being hit by cars, and dingos competing for food.
Tasmanian Devils are widespread and fairly common throughout Tasmania. Found in all habitats on the island, including the outskirts of urban areas, they particularly like dry sclerophyll forests and coastal woodlands. The Tasmanian Devil is a nocturnal and crepuscular hunter, spending the days in dense bush or in a hole. Young devils can climb trees, but this becomes more difficult as they grow larger. Devils can also swim. They are predominantly solitary animals and do not form packs. They occupy territories of 8–20 km², which can overlap considerably amongst different animals.
Tasmanian Devils can take prey up to the size of a small wallaby, but in practice they are opportunistic, and eat carrion more often than they hunt live prey. Although the devil favours wombats, it will eat all small native mammals, domestic mammals (including sheep), birds, fish, insects, frogs and reptiles. Their diet is largely varied and depends on the food available. On average, they eat about 15% of their body weight each day; however, they can eat up to 40% of their body weight in 30 minutes if the opportunity arises. Tasmanian Devils eliminate all traces of a carcass, devouring the bones and fur in addition to the meat and internal organs. In this respect, the devil has earned the gratitude of Tasmanian farmers, as the speed at which they clean a carcass helps prevent the spread of insects that might otherwise harm livestock.
Eating is a social event for the Tasmanian Devil. Much of the noise attributed to the animal is a result of raucous communal eating, at which up to 12 individuals can gather, and can often be heard several kilometers away. A study of feeding devils identified 20 physical postures, including their characteristic vicious yawn, and the 11 different vocal sounds that devils use to communicate as they feed. They usually establish dominance by sound and physical posturing, although fighting does occur. Adult males are the most aggressive, and scarring is common from fighting over food and mates.
Because they were seen as a threat to livestock in Tasmania, devils were hunted until 1941, when they became officially protected. Since the late 1990s Devil Facial Tumour Disease has reduced the Devil population significantly and now threatens the survival of the species, which in May 2008 was declared to be endangered. Programs are currently being undertaken by the Tasmanian government to reduce the impact of the disease.
Some Tasmanian Devils are kept in zoos so humans and other animals cannot kill or hurt them. Now zoos are trying to keep the captive animals safe from the spread of Devil Facial Tumour Disease which produces tumorous growths on the face and muzzle. The disease spreads through biting—a common practice in Devils as they are natural fighters, battling tooth and claw for every morsel of food.
While the Devil numbers are decreasing, fox numbers are increasing. Foxes were introduced, and later they began to hunt and eat Devils. It is believed if the Devil numbers drop too low, then there is little hope the population will ever recover.
Sources: wikinews, wikimedia, Cosmosmagazine.com
Photo Credits: wikipedia