They spread blackberry (an introduced plant and a pest) seeds in
droppings as in the summer they eat the berries due to
availability of resources. They compete against native
predators, such as eagles, and in the past have competed with
Tasmanian Devils, once abundant throughout the mainland, now
only found in Tasmania, and the now extinct Thylacine - Tasmanian
Tiger - Tasmanian Wolf.
Although some animals don’t seem so ‘defenceless’. The Numbat, Western Quoll, Brush-Tailed Bettong and Red-Tailed Phascogale, all found in south- Western Australia (WA) and quite rare everywhere else, are ‘poisonous’ to the Fox. They eat species of plants (Gastrolobium and Oxylobium) that are poisonous to all other animals, particularly the fox. These plants contain Fluoroacetate which is the main poison used in 1080. Since these particular animals have developed immunity to the Fluoroacetate, the poison stores in their flesh, and when a fox eats it, that fox dies.
This canine killing machine has been caught looting loggerhead turtle nests, and eating the eggs in the nests on the beach. These animals are protected and are of particular alarm at Mon Repos Conservation Park in the Hervey Bay region of Queensland. Without the threat of foxes, a small percentage of turtle hatchlings survive to make it to the water after they hatch and then make it to childhood.
The fox is also a carrier of rabies. If this disease were to be introduced it would be devastating to the fragile Australian ecosystem. Rabies is a disease that affects not only animals, but also humans. If rabies was introduced into Australia, with the amount of feral animals, primarily the fox, there would be no hope in eradicating it. The only way that rabies could be introduced to Australia is if an animal that is infected with it is smuggled into the country and comes in contact and attacks a human or animal. From that one animal, thousands, even millions of animals and humans could become infected. It would not take long to infect this many animals.
Recently this feral, canine monster has become established in Tasmania, the island state. The effect that this one animal will have on this beautiful, unspoilt wilderness will be catastrophic.