Exotic Animals - Major Pests
Cane Toad
Family: Bufonidae
Scientific names: Chaunus marinus
Background
Cane toads are native to Central and South America. They were first introduced to Australia (Queensland) in the 1930's as a means of controlling the cane beetle, which was causing significant damage to sugar cane crops. Cane toads have spread fairly rapidly through northern Australia, and they are now located in Queensland, NSW and the Northern Territory. In fact, few people realise that cane toads were first sighted in the Northern Territory in 1984, however, more recent sightings of cane toads in the Darwin region has resulted in greater public interest. Considerable activity is currently being invested into preventing cane toads from spreading into Western Australia.
Cane toads are prolific breeders, which is one of the primary reasons for their considerable invasion success. In addition, they are opportunistic feeders, and their diet comprises of both living and dead matter, such as plants, carrion, dog food, household refuse, small vertebrates, and a range of invertebrates. Other characteristics that add to their invasion success in Australia and in other locations, includes their capacity to live for extended periods away from water, their ability to tolerate sea water for short periods, and their nocturnal activity.
Impacts
The main threat posed by cane toads occurs when other wildlife attempts to eat them. When cane toads are threatened, they release a toxin (bufotoxin) from the glands behind the eyes and across their back. This toxin is present in both the adults and tadpoles, meaning that cane toads may negatively affect a wide diversity of wildlife. While it has been very difficult to quantify the losses to native animals as a result of cane toad invasion, evidence suggests that the Northern Quoll, goannas, snakes, fish, freshwater crocodiles and egrets are particularly affected by the invasion of cane toads. In parts of Queensland, populations of some of these animals were dramatically reduced when cane toads first arrived; although it seems that many have recovered since that time. This recovery has mainly been attributed to a change in behaviour, as native animals have learned to avoid cane toads as a food source.
Other threats to native wildlife include competition with native animals for food and resources and increased spread of disease.
What You Can Do
- Remove cane toad eggs and tadpoles from pools, ponds and water features and place them in the sun to dry out.
- Make sure that the animal that you have captured is actually a cane toad.
- Identify the animal: In the last five years, Wildlife Officers have been called on to identify many suspected cane toads sighted in Darwin. In 95% of these cases, the captured animals were identified as Marbled Frogs or other native species. Marbled frogs are a common native species and their warty appearance and large size fools many people.
- Use a safe method to collect the toad: Cane toads are toxic. The source of the toxins is a large gland on the back of the neck. It is only toxic if ingested or rubbed into eyes. The toxin exudes over the toad's skin, it does not spurt out. Use two plastic shopping bags, or something similar to pick up the toad. Turn the bags inside out, grab the toad, turn the bags the correct way round again, tie the bags tightly and you'll have safely bagged your toad.
- Disposing of the toad: We have all heard stories of how people in other places kill cane toads. The most humane method of disposing of toads is to place your double-bagged toad in the freezer overnight.
For further information, relating to reporting sightings of cane toads, requesting in capturing toads, taking part in Toad Musters or for information on trapping:
Phone: FrogWatch on 1800 243 564
Email: toadreport@frogwatch.org.au
Go to: www.frogwatch.org.au
