Lesson

Cane Toads in Australia

Today’s Aussie fact I thought I would talk about cane toads, and I’m not sure if I’ve talked about these before or not, but maybe you guys have heard of cane toads in Australia. If you go north, you will definitely see cane toads.

So, I recently saw a news article this week about the genome having been cracked for cane toads, meaning that the genome of the cane toad, the DNA sequences of the entire DNA of the cane toad, has been successfully sequenced now, and it got me thinking about the cane toad, and I thought I would go through a number of different facts about it. Okay? And there’ll be a link in the transcript for this article if you’re interested.

Alright, cane toads. So, cane toads are a type of frog and they were introduced into Australia, they are an invasive species in Australia. They are not natural. They aren’t endemic here.

They’re about four to six inches long when they get to fully-grown size and they can weigh up to about four pounds, so close to two kilos, which is pretty impressive for a frog, and the females actually end up a lot larger than the males, and this may not come as a surprise, because females are, obviously, the animal that produces all the eggs. The males produce the sperm. The females produce the eggs. So, they’re egg producers and layers.

Once fully grown, the females can deposit up to 30,000 eggs in a single night. That’s crazy. And it only takes three days, 36 hours, for these eggs to hatch into tiny tadpoles. This is obviously one of the reasons these guys are such successful invasive species.

So, these tadpoles slowly grow their back and their front legs, usually the back first then the front, and they transform into froglets, young frogs, after only four to eight weeks.

They can live up to 10 or 15 years in the wild and up to 35 years in captivity. That’s four years older than me. Crazy!

Cane toads are highly poisonous, though, they’re very dangerous, and produce a toxin in the glands on the back of their neck so that if anyone picks them up or bites them, attacks them, often this toxin, when pressure is put on this gland, is released, it‘s spat out of the frog and it can kill really quickly. So, that’s why there’s such a danger to native animals, especially, animals that hunt them.

So, the cane toad isn’t native to Australia. We established that at the start. And it was ignorantly introduced into Australia in 1935, so 83 years ago, by a man named Reginald Mungomery. So, he brought these over to Australia in a flight from Hawaii where he picked up a 102 of these cane toads, 51 males and 51 females. And this guy was supposedly trying to fix the problem of cane beetles, cane grubs, that were destroying sugar cane crops in northern Australia. So, these insects were eating the crops and he thought, you know, I’ll get some frogs. Obviously, frogs eat insects, and we’ll let them go, and hopefully this will sort out the cane beetle problem.

The problem was that the frogs can’t jump very high, right? So, they became beetles at the top of the cane, the sugar cane, which can be metres high, and the frogs don’t get up that high.

So, these toads were initially released around Cairns and Gordonvale and Innisfail, in Far North Queensland, and shortly after this ‘the march’ of the cane toad began. And this is known as the ‘Invasion Front’ in Australia. I remember this at school always being spoken about. Where the cane toads at now? Which cities or towns are they about to get to?

So, the march of the cane toad moved at about 10 kilometres a year until the 1960s when it significantly began to pick up pace, it began to speed up. By 1945, the cane toads had reached Brisbane, which was 1,600 kilometres south of where they were first released. They started knocking on the doors of people in Byron Bay in New South Wales in 1965. And by 1984, they were stealing the cat food from unsuspecting kitties in the Northern Territory. And in 2009, they finally marched across into Western Australia on the far west of the continent.

So, until today, the cane toad is one of the most catastrophic ecological disasters to have ever happened in Australia, much worse than any other introduced species. Whether it’s rabbits or foxes or donkeys, the cane toad has been devastating.

Despite this, scientists are still hopeful that they can fight against the cane toad by coming up with unique ways to control cane toad numbers. Although, we’ll never be able to completely eradicate the cane toad, hopefully, studies such as the one I mentioned at the start, where the genome has now been completely sequenced, will allow scientists to identify weaknesses in the DNA of the cane toad or maybe in diseases that affect the cane toad, but don’t affect native animals, and they can use these to exploit the cane toad and control their numbers in the future.

So, my question for you today is one: have you ever seen a cane toad in real life if you’ve been to Australia? And two: have you seen the awesome cane toad documentary Cane Toads: An Unnatural History? So, I recommend checking out that doco. It is amazing. And it is full of Australian humor and you will learn a lot about… not just Australia and Australian culture, but also about the cane toad too if you check that out.


Vocabulary:

A cane beetle/grub – an insect that lives on a cane plant – a plant from which sugar is made

A cane toad – a large brown toad native to tropical America. It has been introduced elsewhere as a pest control agent but can become a serious pest itself, partly because animals eating it are killed by its toxins.

A continent – any of the world’s main continuous expanses of land (Europe, Asia, Africa, North and South America, Australia, Antarctica).

A crop a cultivated plant that is grown on a large scale commercially, especially a cereal, fruit, or vegetable.

A disaster – a sudden accident or a natural catastrophe that causes great damage or loss of life.

A DNA sequence – the order of base pairs in a section of DNA – deoxyribonucleic acid

A doco – a documentary

A donkey – a domesticated hoofed mammal of the horse family with long ears and a braying call, used as a beast of burden; an ass.

A fox – a carnivorous mammal of the dog family with a pointed muzzle and bushy tail, proverbial for its cunning.

A frog – a tailless amphibian with a short squat body, moist smooth skin, and very long hind legs for leaping.

A froglet – a baby frog

A genome – the haploid set of chromosomes in a gamete or microorganism, or in each cell of a multicellular organism.

A gland – an organ in the human or animal body which secretes particular chemical substances for use in the body or for discharge into the surroundings.

A kitty – a cat

A layer – a thing that lays eggs

A producer – a thing that creates or makes something

A rabbit – a gregarious burrowing plant-eating mammal, with long ears, long hind legs, and a short tail.

A toxin – a poison of plant or animal origin, especially one produced by or derived from microorganisms and acting as an antigen in the body.

A weakness – a disadvantage or fault.

An invasive species – a species of organism that is not native to a location where it now lives

Captivity – the condition of being imprisoned or confined.

Catastrophic – involving or causing sudden great damage or suffering.

Come as a surprise – to make someone feel surprised, relieved, disappointed etc

Come up with ST – produce (something), especially when pressured or challenged.

Crack ST – achieve ST

Crazy! – said in surprise or shock

Dangerous – able or likely to cause harm or injury.

Deposit ST – put or set down (something or someone) in a specific place.

Despite this… – without being affected by this; in spite of this

Ecological – relating to or concerned with the relation of living organisms to one another and to their physical surroundings.

Endemic – (of a plant or animal) native or restricted to a certain country or area.

Eradicate ST – destroy ST completely; put an end to ST

Establish ST show (something) to be true or certain by determining the facts.

Exploit ST – make full use of and derive benefit from (a resource).

Fight against ST – work counter to ST; fight to prevent ST

Fix ST – mend or repair ST.

Fully-grown – having reached full growth or development

Get to ST – arrive at ST

Go through ST – address all parts of ST systematically

Hatch into ST – (of an egg) open and produce a young animal.

Hawaii – a state of the US in the central Pacific

Hear of ST – be aware of ST

Highly at or to a high degree or level.

Hopeful – feeling or inspiring optimism about a future event.

Identify ST – establish or indicate who or what (someone or something) is.

Ignorantly – resulting from or showing lack of knowledge or intelligence.

Impressive – evoking admiration through size, quality, or skill; grand, imposing, or awesome.

Introduce ST into SW – put or bring ST into SW

Knock on the door – hit the door with your hand in order to tell the inhabitant you have arrived at their house.

Native to SW – naturally occurring SW.

Pick ST up – collect ST; retrieve ST

Pick up (the) pace – increase the speed

Poisonous – (of a substance or plant) causing or capable of causing death or illness if taken into the body.

Produce ST – create or make ST

Released – allow or enable to escape from confinement; set free.

Sequence ST – to use chemistry and machines to determine the precise order of nucleotides within a DNA molecule.

Significantly – in a sufficiently great or important way as to be worthy of attention.

Sort ST out – resolve ST; organise ST

Speed up – increase the speed of ST

Spit ST out – (of a liquid) to project out of ST

Steal ST – take (another person’s property) without permission or legal right and without intending to return it.

Successful – accomplishing a desired aim or result.

Sugar cane – a perennial tropical grass with tall stout jointed stems from which sugar is extracted. The fibrous residue can be used as fuel, in fibreboard, and for a number of other purposes.

Supposedly – according to what is generally assumed or believed (often used to indicate that the speaker doubts the truth of the statement).

Transform into ST – change into ST; metamorphose into ST

Unsuspecting – (of a person or animal) not aware of the presence of danger; feeling no suspicion.

Up to ST – indicating a maximum amount.