Cane Toad
Chaunus marinus (= Bufo marinus)
Cane Toads are native to North, Central and South America. They are sometimes called Giant Toads, appropriate because of the size of some females; they can weigh up to 2.5 kg and be 26 cm long.
The eggs and tadpoles of Cane Toads are very distinctive. Their eggs are small, black and numerous, found in 'strings of jelly' deposited on the bottom of ponds or pools of water. They develop in most types of water: fresh or brackish; still or running; clear or muddy; deep or shallow; and in swimming and ornamental pools. Their tadpoles are also black, small and numerous; they swim together in groups.
Cane Toads produce a cocktail of highly-toxic, biologically-active substances. These substances are concentrated in their 'warty' skin and are secreted by two large parotoid glands behind the eyes. Toxins are also present in muscles, bones and body organs, and in their eggs and tadpoles. Cane Toads are passive and not harmful when left alone, but their toxins are very dangerous if eaten or rubbed into the skin or the eyes.
Cane Toads were introduced to Queensland as a biological control for cane beetles in sugar cane crops. They have become a serious threat to our native wildlife, particularly to animals that feed on frogs. A handful of native animals can eat them and survive, and these include the Snapping Turtle, Wollumbinia latisternum; the Freshwater Snake, Tropidonophis mairii; the crocodiles, Crocodylus porosus and Crocodylus johnstoni; the Water Rat, Hydromys chrysogaster; and some birds such as ibises and the Torresian Crow, Corrus orru.
The full impact of Cane Toads on our wildlife may never be fully appreciated. They have spread rapidly from the places where they were released, and continue to advance south and west across Australia. It is difficult to separate their impact from that caused by human population growth: the clearing and degradation of native vegetation, waterway pollution and the spread of introduced plant and other animal pests. They are now considered pests.
Removal and humane disposal of Cane Toads from your local area may help reduce their numbers.
Please ensure that you are identifying "toads" correctly. If there is any doubt, please contact the Queensland Museum or the Environmental Protection Agency for advice.
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