Cane Toads are present in the Daintree lowlands (between the Daintree River and Cape Tribulation). They find a moist cool place to hide during the day and they prefer urbanised areas, around houses and gardens with mown lawns. This is because they find it difficult to move through tall vegetation as they are not very good at climbing and jumping and also because lights attract insects.
Cane Toads (Rhinella marina) are originally from South America and 102 were introduced in Australia in 1935 by the Queensland government to control cane beetles in sugar cane plantations (it didn't work). An unintended outcome is the population of Cane Toads has now spread to different regions of the country and is present in urban areas, but also in coastal dunes, woodlands, rainforests, and freshwater wetlands.
In Australia, Cane Toads don't have a “natural enemy”, which makes their reproduction easier and faster. From only 102 individuals in 1935, they increased to 62,000 in 1937 and now they have become around 200 million. One female can lay up to 90,000 eggs a year. Only one in 200 eggs will survive however individual Cane Toads can live up to 16 years. They are well established in Queensland and New South Wales and are migrating through the Northern Territory at a rate of 40 km a year and have reached Western Australia.
As an introduced exotic species, Cane Toads are a problem because they are toxic and they poison and kill all their predators. They also eat small reptiles, insects, and other amphibians, and displace native species as they compete for food and resources to survive. The toads' poisonous tadpoles and eggs kill aquatic creatures.
However – all is not lost – nature is fighting back. Not only are a number of birds and animals finding ways to safely eat Cane Toads, they are becoming infested with a range of parasites – one came with them (lungworm), but a number hopped from native frogs to the new host. Any scrawny little Cane Toads you see are probably loaded with parasites (they won’t affect us).
Cane Toad appearance:
It's important to know the difference between a native frog species and a Cane Toad. Here's what you need to know. They are;
- Coloured brown, olive-brown or reddish
- Have thick, leathery skin with warts
- A visor or awning over each eye
- A bony ridge that extends from eyes to nose
- Small feet, with claw-like un-webbed digits to dig
- Two large toxin-filled parotid glands behind the ears
- They may appear dry, are heavily built, and can reach up to 20 centimeters long
- Have a very loud and distinctive mating call, a bit like a musical motorboat (produced by the male).
Controlling Cane Toads
Cane Toads require water to breed (like most frogs). However the soil in much of the Daintree lowlands is sandy, and water doesn’t pool after rain, so depriving the toads of suitable places for their eggs to develop. However – your ornamental pond or pools of water in your garden just might be an ideal breeding site!
To reduce the number of Cane Toads residents and land managers in the Daintree lowlands can do a few simple things.
- Remove places they can breed - still water, puddles, etc
- Place pet food out of reach
- Reduce lawns and increase rainforest habitat
- Cane toads, unlike our native frogs, lay their eggs in long gelatinous strings, which are easy to recognise and scoop out (just lay them somewhere where they will dry out).
“Cane toads can be collected and removed by hand. Traps and barrier fencing can be used to contain them but vary in effectiveness. According to recent research by the University of Sydney, refrigeration followed by freezing is the most efficient, effective and humane method of Cane Toad euthanasia”, explains the NSW Department of Planning and Environment.
Two highly recommended videos.
Do you have more information about Cane Toads in the Daintree lowlands?
Please, share your knowledge of Cane Toads in the Daintree Lowland Rainforest so that we can improve our understanding of the issue. Email us at [email protected]