The dodo is extinct for a number of reasons. When humans settled permanently on Mauritius, they cleared native dodo habitat, destroying nesting grounds. They also introduced
… various new species, all of which were a threat to the dodo. Dogs and pigs killed the birds; cats and preyed on the young chicks; and Crab-eating Macaques were introduced from Asia - these ate the eggs of the dodo. The Thylacine , also known as the Tasmanian tiger, is extinct because the European settlers feared it was killing their livestock. A bounty was placed on it, so it was hunted to extinction. Scientists have also proposed the theory that, by the time the Thylacine was limited to just Tasmania, the remaining specimens did not have sufficient genetic diversity to sustain the population. A similar problem is currently affecting the Tasmanian devil, resulting in the spread of the fatal DFTD, or Devil Facial Tumour Disease. There were once two species of bilby in Australia, but now there is just one. The Lesser bilby became extinct for several reasons. Expansion of agriculture pushed these bilbies back so that they could only live in deserts. Then, they became prey for introduced foxes and cats. The introduction of the rabbit, which voraciously eats much of the vegetation the Lesser bilby ate, reduced its food sources. Rabbits also dig burrows which cause problems for the bilby's habitat, as they tend to cause the bilbies to be caved in. The bilby's habitat has also suffered from being trampled on by herds of stock animals. Currently, there is just one type of emu, but there used to be three known species. Two species of dwarf emu inhabited Kangaroo Island (off the South Australian coast) and King Island (in Bass Strait) but they became extinct once whalers began visiting and settling the area. The whalers hunted the emus for food. The Toolache wallaby was a particularly attractive wallaby of Australia. It became extinct for two main reasons. It was hunted for its fur and for sport. The main factor that led to its extinction, though, was habitat clearing, the loss of native vegetation and the fact that its habitat was changed so drastically through being drained. Swampland was important in the Toolache wallaby's habitat, and these regions were drained for agriculture. (MORE) 
