Eric Shackle's Column

By Eric Shackle

Millions of highly venomous cane toads are invading northern Australia, killing countless small native and domestic animals. Men and dogs hate them.

Cane toads would never win a beauty contest. In fact, they’re hideous.

John Burey, of Charleville, Queensland, sends vast numbers of the pests to China, where they are eaten or their toxin is used as a traditional medicine.

We asked John if he had ever tasted a cane toad, and how they’re caught.

He replied, “I’ve eaten quite a few of them in China, where they’re kept in captivity and feed on worms. To catch them, just walk around in the evening with a torch and gloves.”

An Australian website, All About Dogs, says:

"Toads exude a milky white toxin from poison glands behind their eyes. They squeeze this poison onto the surface of their skin when they are under threat. Toads do not spit or squirt the poison as commonly believed, and they don’t bite. Dogs and cats are poisoned when they mouth the toad or sometimes when the toad’s poison gets into their eyes.

"The toad’s poison is also dangerous to humans and deaths have occurred. Some adults have even been affected when they absorbed the poison through cuts in their skin after handling a toad.

"In China, they have used toad poison as an expectorant, a heart stimulant and as a diuretic. It has also been used as a remedy for toothache and sinusitis. In Africa and South America, toad venom has been used on the tips of arrows as a poison.

"Dogs may be poisoned by oral exposure to many types of toads. All toads produce venom but toxicity varies greatly by species.

"The most important species of concern in the United States is the giant or marine toad Bufo marinus, ( a.k.a. bufo toad ) an introduced species that has established itself in Hawaii, Florida and Texas.

"Local effects include shaking of the head, pawing at the mouth, retching and frothy salivation. Severe intoxication as from the Bufo toad may include life threatening cardiac and CNS involvement.

"Toads were introduced into Australia in 1935 to control the cane beetle - a disastrous move, as toads have no natural enemies in Australia.

"Australian Terriers and Fox Terriers also think this was a dumb idea, as they are the breeds most often affected by toad poisoning.

"The Cane Toad is Australia's only true toad, it grows to a massive 24cm and can lay up to 40,000 eggs in one season. Most native tadpoles cannot live in the same water as the poisonous Cane Toad tadpoles. Each female cane toad lays up to 40,000 eggs a month, and half that number can expect to develop into tadpoles within three days.

"The largest cane toad on record in Australia was 16.5 cm wide, 24cm in length and weighed 1.36kg.!

An article on The Australian Museum (Sydney) website says:

No humans have died in Australia from cane toad poison but overseas, people have died after eating toads and even soup made from boiled toad eggs.

Cane toads are also poisonous to pets and in Hawaii up to 50 dogs a year have died after mouthing cane toads. Signs of poisoning through ingestion include profuse salivation, twitching, vomiting, shallow breathing, and collapse of the hind limbs. Death may occur by cardiac arrest within 15 minutes.

Australian native fauna that have been killed by eating or mouthing cane toads include goannas, freshwater crocodile, tiger snake, red-bellied black snake, death adder, dingo and western quoll.

A cane toad responds to threat by turning side-on so its parotoid glands are directed towards the attacker. The poison usually oozes out of the glands, but toads can squirt a fine spray for a short distance if they are handled roughly.

The poison is absorbed through mucous membranes such as eyes, mouth and nose, and in humans may cause intense pain, temporary blindness and inflammation.

First aid treatment includes irrigating (washing with a lot of water) the eyes, mouth and nose if they have been exposed to toad poison.

Seek medical attention if symptoms persist. When handling any frog or toad, protect the eyes, wear gloves, and thoroughly wash hands before and after touching the animal.

The cane toad has mounted a successful invasion in Australia and many other countries - but where did the toad come from originally? These toads have a wide native range in Central America and South America. Studies on DNA characteristics of Aussie toads suggest that they descend from a group of toads originally collected from South America (perhaps French Guyana).

These were taken to Puerto Rico, then toads from that island were taken to Hawaii – and finally, 101 Hawaiian toads were brought to Australia to form the beginnings of the invasion.

A message from Hilbilly NC on an American online forum says, "Most toads have poison glands in their skin, some have pretty potent toxins. I've heard of Cherokee cleaning toads by holding them under swift running water, twisting their heads off and skinning them while keeping them under the current. I think I'd have to be pretty damn hungry to try it, though.
I really like frog legs."

LINKS:
Hopping mad: http://www.theaustralian.com.au/news/cane-toad-spat-leaves-slayers-hopping-mad/story-e6frg6n6-1226599838178

Save Our Frogs: http://allaboutfrogs.org/info/save/whattodo.html

Cane toad video: http://www.youtube.com/watch?v=4mvV8OT-mmE

Kimberley Ark: http://www.abc.net.au/am/content/2013/s3719551.htm

Toad sausages: http://news.bbc.co.uk/2/hi/science/nature/8640207.stm

Cane toads in Oz : http://www.canetoadsinoz.com/

From ERIC SHACKLE, in Sydney, Australia. Posted Saturday, 16 March 2013, at 18:07.