Background:
Cane Toads, Bufo marinus, are amphibians native to freshwater grasslands in Central America and Tropical South America. They are omnivores and live 5-10 years in the wild. These toads were introduced in Australia in 1935 in order to try to control the vicious Cane Beetle population, which at the time, was damaging the sugar cane crops, a major source of income for the country. Approximately 3,000 Cane Toads were released into sugarcane plantations, however, today their population size is in the millions.
Cane Toads are venomous and have parotid glands behind their ears. In their native land, these glands are used for protection against predators. However, this poisonous toxin can be dangerous, most commonly affecting the functioning of the heart, to many other species.
Predators of the Cane Toad in Central and South America include snakes, caimans, eels, and certain fish. These predators are usually immune to their venom or avoid eating the poisonous parts. These toads reproduce very quickly: a female lays 4,000-36,000 eggs at a time (in one pond) and the tadpoles hatch within 3 days and become fully developed after metamorphosis in 12-60 days. Due to this quick reproductive process and no predators to control the size of the population, the number of Cane Toads in Australia has quickly and easily increased over time.
For more information concerning the Cane Toad invasion, watch this video:
http://www.animalplanet.com/tv-shows/weird-true-and-freaky/videos/cane-toad-australian-invasion.htm
Cane Toads, Bufo marinus, are amphibians native to freshwater grasslands in Central America and Tropical South America. They are omnivores and live 5-10 years in the wild. These toads were introduced in Australia in 1935 in order to try to control the vicious Cane Beetle population, which at the time, was damaging the sugar cane crops, a major source of income for the country. Approximately 3,000 Cane Toads were released into sugarcane plantations, however, today their population size is in the millions.
Cane Toads are venomous and have parotid glands behind their ears. In their native land, these glands are used for protection against predators. However, this poisonous toxin can be dangerous, most commonly affecting the functioning of the heart, to many other species.
Predators of the Cane Toad in Central and South America include snakes, caimans, eels, and certain fish. These predators are usually immune to their venom or avoid eating the poisonous parts. These toads reproduce very quickly: a female lays 4,000-36,000 eggs at a time (in one pond) and the tadpoles hatch within 3 days and become fully developed after metamorphosis in 12-60 days. Due to this quick reproductive process and no predators to control the size of the population, the number of Cane Toads in Australia has quickly and easily increased over time.
For more information concerning the Cane Toad invasion, watch this video:
http://www.animalplanet.com/tv-shows/weird-true-and-freaky/videos/cane-toad-australian-invasion.htm
Harmful Effects:
The Cane Toads in Australia are unable to reach up to all of the Cane Beetles that were able to climb to great heights, which they were supposed to consume when first introduced. Therefore, they uncontrollably eat any possible source of food since they are opportunistic feeders. Sometimes they eat pet food and steal from bowls left outside of human's homes. In Australia, Cane Toads are causing the depletion of other species (because of their poisonous venom and since they eat as much wildlife as possible). Specifically, these toads have significantly reduced the population of the prey called skunks, or a type of lizard. Listen to the Cane Toad's Call http://www.wec.ufl.edu/extension/wildlife_info/frogstoads/wav/giant_taod.wav |
Potential Future Dangers:
Australian reptiles are the most threatened due to the invasion of the Cane Toad. Their increasing population has already proved to be detrimental for Australia and if not contained, could pose a critical threat to other species in close proximity that interact with the Cane Toad. Some native species such as the Torresian Crow have adapted to learning how to consume the toad without ingesting the poisonous venom. However, for the most part, the Cane Toad could prove detrimental to both plants and animals in Australia and provide reverse effects to what they were originally intended for. Cane Toads can poison or injure other animals with their toxins, prey on native vegetation, compete for food with insectivores, and may carry diseases that can be spread to other frogs or fish. A study found that about 75 species are at a risk from the Cane Toad invasion in Australia. These include several species of crocodile, 14 species of tortoise, 37 species of agamid, and 22 species of varanid. 34 of these 75 species are projected to have their habitat encompassed by 2030 (as predicted according to climate change models). 7 of these species already have their habitat entirely encompassed. |
Solutions:
Kakadu National Park, located in northern Australia, has established research sites to provide information that can help lead to effective management of the Cane Toad and its impacts. Their studies assess findings and determine possible solutions to control the Cane Toad population. Additionally, the Vertebrate Pests Committee under the National Resource Management Ministerial Council is reviewing the threats of Cane Toads and using research to lessen the threats.
Another idea includes introducing a native viral or bacterial pest, however this could potentially introduce new problems. Also, introducing a gene into a female toad that only allows her to reproduce male offspring would limit the population diversity.
Moreover, scientists at the University of Adelaide have found a sex pheromone that could be used to disrupt the rapid breeding cycle of Cane Toads and scientists from the CSIRO Animal Health Laboratory in Victoria have investigated gene technology as a mechanism of control.
Kakadu National Park, located in northern Australia, has established research sites to provide information that can help lead to effective management of the Cane Toad and its impacts. Their studies assess findings and determine possible solutions to control the Cane Toad population. Additionally, the Vertebrate Pests Committee under the National Resource Management Ministerial Council is reviewing the threats of Cane Toads and using research to lessen the threats.
Another idea includes introducing a native viral or bacterial pest, however this could potentially introduce new problems. Also, introducing a gene into a female toad that only allows her to reproduce male offspring would limit the population diversity.
Moreover, scientists at the University of Adelaide have found a sex pheromone that could be used to disrupt the rapid breeding cycle of Cane Toads and scientists from the CSIRO Animal Health Laboratory in Victoria have investigated gene technology as a mechanism of control.