Introduced Species to the Australian Environment

Only available on StudyMode
  • Topic: Cane toad, Pig, Wild boar
  • Pages : 9 (3022 words )
  • Download(s) : 88
  • Published : October 1, 2012
Open Document
Text Preview
-------------------------------------------------
Introduced specices and the australian environment

Gather, process, analyse and present information that reports on TWO animal and TWO plant species that have been introduced into the Australian environment -------------------------------------------------

Introduced specices and the australian environment

Gather, process, analyse and present information that reports on TWO animal and TWO plant species that have been introduced into the Australian environment

Cane Toads
Wild Boars
Prickly Pear
Blackberry
Cane Toads
Wild Boars
Prickly Pear
Blackberry

Cane Toads
In 1935 The South American Cane Toad was introduced from Hawaii, specifically to control the native pest, the Cane Beetle, which was eating one of Australia’s largest income crops the Sugar Cane. The adult cane beetles eat the crop's leaves, but the main problem is the larvae, who feed on the roots. The adults exoskeleton beetle is extremely thick and they lay their eggs underground so, the only alternative in the eyes of the Bureau of Sugar Experiment Stations was to introduce the Cane Toad, The toad naturally having an appetite for these bugs, would then eat the them, thus not requiring the use of heavy chemicals or other pesticides that could build up in the soil and kill other native surrounding flora and fauna. Currently, Cane toads migrate at an average of 40 kilometers per year and have successfully adapted to the tropical climate of northern Queensland and are beginning to make their way down to the NSW border in 1978, and then the Northern Territory in 1984. The toads that are on the western side of their advance have evolved larger legs; Scientists believe that this is related to their ability to travel farther. Now, as a consequence of their longer legs, larger bodies, and faster movement, about 10% of these cane toads have in turn developed arthritis. Some studies however, note that the cane toad is adapting to a wider environmental range and may in the future be spreading into habitats currently not available

It is hard to determine the long term effects of Cane Toads on the Australian environment, although the obvious results include such things as the depletion of natural species that are preyed on by the cane toad, and the poisonings that result from contact with the toad. Specific declines in the population of the Northern Quoll, Goanna and Snake have been observed after the invasion of Cane Toads to a specific area. Kakadu National Park have done a preliminary risk assessment on the cane toads impact on biodiversity of native species and the results show great risk . Although the Cane Toad preys and has great impact on many native species, there have been reports of many of these species successfully preying and sustaining themselves on the toad. These species include such birds as the Black Kite, which has learned to attack the toad’s belly and avoid the poison glands. A northern territory species ‘Dahl’s Aquatic Frog’ is able to eat the tadpoles and live young of the cane toad without being effected by the poison that normally kills other predators, this could account for the slower than expected infestation rates in some parts of NT, although some experiments carried out by several Australian Universities casts doubt on these reports. Some snakes have been reported to have adapted smaller jaws so that they are unable to swallow large cane toads which have large quantities of poison. So far, most attempts to stop the invasion of cane toads have been unsuccessful. Many of these strategies involve the physical trapping of toads. The largest selective pressure on cane toads currently is interspecies competition (When one animal of a species competes with another animal of the same species). The problem with physical removals is that they often only improve the conditions for other toads that aren’t trapped. Also, since migration is high, any area completely irradiated of toads...
tracking img