They are shot, trapped, poisoned by sheep and cattle farmers. No wonder that the Australian wild dog, the dingo, is menaced. Ecologists warn that pure breed animals may vanish in 40-100 years, due to the cross with the ordinary dogs. By now, the main issue is the proliferation of the hybrids. Dingoes mate once a year, while the hybrids, just like ordinary dogs, do it twice a year.
In 2006, a research showed that the decreased number of dingoes is harmful for the declining native marsupial mammals. Since the European settling in Australia, with their array of introduced species, including foxes and feral cats, the extinction of 18 species of marsupials has been documented; half of all mammals' extinction worldwide occurred during the last two centuries, when also many more species have severely declined.
The Dingo (Canis lupus dingo) was brought to Australia 3,500-4,000 years ago by Malayo-Polynesian seafarers from Indonesia, and traces its roots from a semi-domestic dog in Indochina, very close to wolf races of South Asia. The social dingo hunts in packs but also scavenges. A dingo weighs 10 to 24 kg (22-53 pounds) and is between 44 and 63 cm (17-25inches) high.
At the moment of their introduction, they were probably responsible for the elimination of the extinct thylacine (Tasmanian "wolf"), Tasmanian devil and marsupial lion from Australia, and, moreover, their entrance on the Australia's ecosystems must have provoked the same wave of decline in marsupial species like the recent introduction of foxes and cats, but after the initial moment, a balance was achieved.
Australia's last native "top predators" now perform an essential role in maintaining biodiversity. Marsupial populations have a much better chance to survive in areas that also have stable populations of dingoes, because they are the only predators to control the populations of foxes and feral cats, stopping the overkill of the marsupials.
Dingoes are indeed not compatible with sheep farming, but in cattle country dingoes will hunt kangaroos or rabbits. If there's an alternative prey available, they will leave the cattle alone. Oppositely, sheep are easy to kill, making their preferred prey. Still, sometimes dingoes do kill calves. But people should make a trade off all the costs and all the benefits of having a predator. Dingoes also check populations of animals that compete with cattle, like kangaroos, feral goats and feral pigs.
The disappearance of the marsupial "tiger"
The marsupial "tiger" (called like this because of its striped back) or "wolf" (due to its superficial resemblance to a wolf or dog) stood about 60 cm (23.6 in) at the shoulder and weighed 20 to 30 kg (44-66 lb), doubling a dingo. But strength resulted to be more important than size, enabling dingo to kill larger preys, to outmatch the thylacine.
The thylacine had a more powerful and efficient bite than the dingo, but it could not kill larger struggling prey because of its weak neck. The neck differences enabled the dingo to wipe out the 4 million-year old thylacine. The bigger marsupial meat eater could have smashed small prey relatively easier but it was confined to it, despite its larger size, because it could not subdue large prey, and adult kangaroos and emus could not have counted in its menu. Instead, these species are part of the dingo diet. When a kangaroo is attacked by a dingo pack, it tries to escape in the water, where it can drown its attackers, or it defends itself with powerful kicks and tearing with the claws of the fore limbs, but kangaroos rarely escape if caught.
The dingo was also in advantage because of the social structure and hunting in packs (just like any other wolf), while the thylacine hunted all by itself. The thylacine's extinction on the Australian mainland could have been hurried also by a climate change and a shift in Aboriginal land-use patterns. It persisted only on the island of Tasmania, far from the reach of dingoes, until the European colonization, as the wolf-like carnivore was believed to be able to kill sheep (fact infirmed by the studies).
Exported to zoos, killed by farmers and hunters (up to 2,000 government bounties were given between 1888 and 1912), the Tasmanian population of about 5,000 thylacines disappeared quickly: the last one died in a Tasmanian zoo in 1936. The settlers too competed against the thylacines for food, as they chased small animals, decreasing their numbers, and induced environmental changes.