Animals

Published on November 11th, 2009 | by Yellow Magpie

0

The Cane Toad: Man’s Gamble At Controlling Nature

Cane Toad Photo By Geoff Gallice

Sometimes people take risks in order to solve a particular problem. We make calculated decisions that may have bad consequences for us on a regular basis.

However, hindsight is an overrated commodity. In retrospect is it very easy to say ‘that was a disastrous idea’. Sometimes things just don’t work out the way we planned for whatever reason. That certainly was the case with the introduction of the Cane Toad in Australia.

Cane Toad Found Florida Photo By Bill Waller Creative Commons ShareAlike Licence

However, others cite them as a case in point on unforeseen circumstances when man tries to control nature.

Pest Controller Becomes Pest

There are in excess of 100 million cane toads in Australia. What’s more, their population is continuing to grow.

1935 was the year in which the toad was introduced to northern Queensland, Australia, in the hope of combating the cane beetle. The beetle was destroying the sugar cane crop.

However, hope soon turned to despair as the locals realised that the toad was not doing anything to the beetle population. Worse was to come when toad numbers spiralled out of control and this was to have a devastating impact on native wildlife. In its natural environment, cane toads have many predators which help to curb its population.

Cane Toad Distribution Blue Is Native Red Is Introduced Photo By LiquidGhoul Creative Commons ShareAlike Licence

Poisonous Nature

The Cane Toad is highly toxic. They have a large parotoid gland behind their eyes which when they are threatened secretes a milky fluid called bufotoxin. The Cane Toad is considered to be a pest largely because its toxic skin kills animals if it is eaten.

Rodents, reptiles, birds, plants and rubbish comprises just a portion of their diet. Even large crocodiles have fallen victim to the toxins of the Cane Toad after eating them.

Utilitarian Hunters

Although they are mainly visual hunters they can detect their prey using their olfactory sense. They have a utilitarian diet in that will eat almost anything.

Cane Toad Photo By Sam Fraser-Smith

Amazing Adaptability

The cane toad population was kept under control in Central and South America, where they are native species, by predators and high competition.

In Australia the cane toad faced none of these obstacles. With little or no predators it was able to adapt exceedingly well to its new environment. Australia’s large road network provided the perfect way for the toad to travel. With roads, they could farther than they would be able otherwise in the bush. As a result their physiology changed. They legs grew longer in length and this allowed them to travel even further each day.

Australian Nightmare

Cane toads reproductive cycle means that they hold a greater advantage then native frog species. Producing over four times more eggs that Australia frogs, they are a series threat to the native amphibians. What’s more cane toad tadpoles are poisonous which means they are unlikely to be eaten.

Cane Toad Photo By Brian Gratwicke

Therefore, much more tadpoles are likely to reach maturity as a result. Because of the nature of the toad’s diet, they will eat anything, frog populations in Australia are in danger.

Measures To Curb The Cane Toad

Australia has started to take action and control the cane toad numbers. People gather in groups of ‘toadbusters’ and hunt down the animal. Captured toads are turned into fertiliser. Anti-Animal Cruelty advocates have condemned practices such as ‘Cane Toad Golf’ which still continues.

This is a practice in which the toads are used as golf balls. It is hoped that by curbing the toad populations using control measures the native animals will recover. As of yet, the cane toad has not caused any animal extinctions.

Cane Toad Photo Froggydarb Creative Commons ShareAlike Licence

Beneficial Use

However, cane toads are not all bad news and they do have many positive benefits. In many other countries they have been successfully used as a natural form of pest control. In South America the toad is used by natives as a toxin to kill animals on hunts. The toad would be ‘milked’ and its toxins placed on arrowheads.

In the 1950’s they were used as a pregnancy test. Women would urinate on male toads lymph sacs. If she were pregnant the hormones in the urine would trigger the presence of sperm in the toad’s urine.

They also continue to serve for scientific testing and educational purposes.

Cane Toad In El Salivado Photo By Eli Greenbaum Creative Commons ShareAlike Licence

Vital Statistics

• Typically, Cane Toads measure up to 15 cm (six inches) in length. However, one particular specimen was recorded at 38 cm (15 inches) and 2.6 kg (5.8 lbs).
• They can live up to 15 years in the wild but live much longer in captivity.
• Cane Toads (Bufo marinus) are native to Central and Southern America. However, thanks to breeding programmes they are now found in the Caribbean islands, Australasia and the United States.

Further Reading

The Cane Toad: The History and Ecology of a Successful Colonist is the most comprehensive book available devoted exclusively to Cane Toads.

However, it is quite expensive and a further publication Cane Toads and Other Rogue Species promises to be a much better buy in terms of value for money when it is released later next year.

Amazon.co.uk
For people living in Ireland or the United Kingdom you can access The Cane Toad: The History… and Cane Toads And Other Rogue Species here:

Amazon.ca
For those living in Canada you can obtain The Cane Toad: The History… and Cane Toads And Other Rogue Species from here.

Amazon.de
For Germany: The Cane Toad: The History... and Cane Toads And Other Rogue Species.

Amazon.fr
For France: The Cane Toad: The History….

About the Author

Yellow Magpie

Related Posts

Hector’s Dolphin: New Zealand’s Small Resident Dolphin →

Chilean Dolphin: The Small Dolphin That Avoids People →

Heaviside’s Dolphin: South Africa’s Reticent Dolphin →

Commerson’s Dolphin: One Of Nature’s Most Colourful Dolphins →