Cane toads in Australia
[1] In the Environment Protection and Biodiversity Conservation Act 1999, the Australian government listed the impacts of the cane toad as a "key threatening process".
[3] Based on her findings, they were introduced to Hawaii by Cyril Pemberton in the early 1930s, and then introduced to Australia from Hawaii in June 1935 by the Bureau of Sugar Experiment Stations, now Sugar Research Australia, in an attempt to control the native grey-backed cane beetle (Dermolepida albohirtum) and French's beetle (Lepidiota frenchi).
Adult cane beetles have a heavy exoskeleton and their eggs and larvae are often buried underground, making them difficult to exterminate.
The success of using the moth Cactoblastis cactorum in controlling prickly pears in Australia led to the hope that the cane toad would perform a similar function.
[6] In June 1935, 102 cane toads (Rhinella marina, formerly ICZN Bufo marinus) were imported to Gordonvale from Hawaii, with one dying in transit due to dehydration.
[9] Not only has the introduction of the toads has caused significant environmental detriment, but there is no evidence that they have affected the number of cane beetles which they were introduced to prey upon.
In March 2001, the invasion front entered the wetlands of the heritage-listed Kakadu National Park and, by 2009, the toads were close to the Northern Territory/Western Australian border, and by 2011 had become established in irrigation areas around Kununurra, in WA's north.
[14] The toads on the western frontier of their advance have evolved larger legs,[15] which is thought to be related to their ability to travel farther.
As a consequence of their longer legs, larger bodies, and faster movement, about 10% of the leading-edge cane toads have also developed arthritis.
[18] In 2023, rangers discovered a female cane toad in Conway National Park in north Queensland which, recorded unofficially at 25 cm and 2.7 kg and dubbed 'Toadzilla', may be the largest ever seen.
[26] In the Northern Territory, goanna deaths resulting from poisoning after predation on cane toads has been linked to a rise in the number of undamaged saltwater crocodile eggs.
Some birds, such as the black kite (Milvus migrans),[29] have learned to attack the toad's belly, avoiding the poison-producing glands on the back of the head.
[32] This may account for slower than expected infestations of toads in certain areas of the Northern Territory, although later research carried out jointly by several Australian Universities casts doubt on these reports.
[34] Another study, however, notes that the cane toad is adapting to a wider environmental range and may in the future be spreading into habitats currently not available.
[40] In 2014, researchers found evidence that the Australian freshwater crocodile (Crocodylus johnstoni) had learned to eat just the hind legs of cane toads.
[43] Richard Shine is using behavioural conditioning techniques to teach the northern quoll to avoid cane toads.
[44] In 2019, the native rakali or Australian water rats (Hydromys chrysogaster) were found to have learned to make an incision to eat the cane toads' hearts and livers, while avoiding their lethal skin and glands.
The traps are placed in the shallow edges of bodies of water, and are able to catch thousands of cane toad tadpoles within hours.
[48] Some local and state government bodies have been promoting the usage of such traps by residents to curtail spread of toads without impacting on the tadpoles of other frogs.
[53] Due to concerns over potential harm to other Australian wildlife species, the use of Dettol as pest control was banned in Western Australia by the Department of Environment and Conservation in 2011.
The Western Australian Department of Environment and Conservation has been working with the University of Sydney to develop baits to train native animals not to eat the toads.
Researcher David Pearson says trials run in laboratories and in remote parts of the Kimberley region of WA are looking promising, although the baits will not solve the cane-toad problem altogether.
[56] By 2023, field research indicated that the taste aversion project had not been effective in reducing toad-induced northern quoll decline in the Kimberley.
In April 2005, Dave Tollner, a Northern Territory Member of Parliament, called for legalisation of attacks on cane toads.
This was criticised by many animal and conservation groups, who claim freezing is a more humane way to kill cane toads than hitting them with cricket bats.
[citation needed] A controversial commercial for Tooheys beer company showed people from New South Wales standing at the New South Wales-Queensland border with golf clubs and lights, attracting cane toads just so they could hit them back across the border with the golf clubs.
