Cane Toads

By Chantelle Eikelboom and Mitchell Barber

What are the effects of cane toads in Australia?

Research Questions

1. How fast are the cane toads spreading and which parts of Australia have been affected the most?

2. Why did no one consider the fact that the cane toads might have a negative impact on the environment when they were introduced into Queensland? Did the cane toads have negative impacts in the areas where they came from?

3. What impact are cane toads having on animal populations?

4. If any, what positive impacts did the cane toads have?

History and Movement

• Introduced by Reginald Mongomery in 1935 from Hawaii

• Cane toads didn’t help cane growers with their beetle problem

• Toads are now moving at 40-60km per year due to evolution of longer legs

Effect on animal species

• Large animals such as snakes, crocodiles and some mammals are most at risk

• They are a contributing factor to population decline in some species

Red Belly Snake

Cane Toad

Northern Quoll

Conclusions

• Cane toads didn’t help farmers and are now a widespread pest across much of Australia

• They are currently moving at 40-60km per year

• They are affecting many animal populations, mostly large animals

How to control the cane toads in Australia?

What is the problem really?...

…Their Reproduction Rate

Research Questions

1. What is the effectiveness of toad busting, toad traps, and fencing to control the magnitude and spread of cane toad populations?

2. Do cane toads have any natural predators in Australia, and can we utilise any of these to combat the cane toads?

3. Are there any other ways to battle the cane toad advancements and population growth on a more scientific level, e.g. biological warfare?

Physical SolutionsToad Busting:• Is a method that is very effective at moving large numbers of cane toads

quickly from an area (4,500 cane toads in 3 hours in one spot) (Toad Busting hand or Collection, 2011)

• However, due to their rapid reproduction rate, even if 99% were removed, their numbers would return to pre-harvest level very quickly (“Cane Toad tadpole control”, 2011-2012, para.1)

Fencing:• Is a very effective mechanism for keeping cane toads out of water bodies

and thus depleting their reproduction rates• However, this is not effective in all parts of Australia such that this will

provide a negative impact on other wildlife speciesToad traps:• Due to cane toads characteristics such as feeding on insects, traps prove

to also be effective at depleting cane toad numbers in an area

Biological Solutions

Meat ants:

• Love to eat cane toads • An interesting fact about meat ants and cane toads

is that they both “spend their time active by day in exactly the same places” (“MEAT ANTS: an Aussie predator”, 2011-2012, para. 2)

• Researchers found that the was no increased impact on native species when the number of meat ants increased in the area

Biological Solutions

Scientists have found that the exposure to cane toad tadpole pheromones results in physical defects, e.g., lower body mass. Additionally, tadpoles exposed to this chemical suffer and decrease in survival rate by 40% (“Ecology: Chemical warfare among cane toads”, 2011, para.2)

Toads are attracted to their own poison

Scientists have been testing its effectiveness in traps. In one test, results had shown that over 40,000 cane toad tadpoles were captured in less than a week

Conclusions

• These various physical solutions to control the cane toad populations are effective, however, something else is needed

• Research shows that the problem actually lies with the rapid reproduction of cane toads

• Once a solution can be found for this, a combination of the solutions would prove to be very effective in the war against cane toads

Curriculum

SU• Biological sciencesSI• Developed research questions• Evaluate and analyse data for validity SHE• Decisions influenced by society

Sustainability

Sustainability is meeting the current social, environmental, economic and political needs of current generations without compromising the

ability for future generations to meet these needs

Reflections

My two ‘s include:• There were many articles written about my topic

which were very useful • I know so much about cane toads now

My one wish would be to be able to get more stats and current information.

Reflections

My two ‘s include:• I found this topic really intriguing such that I began

emailing researchers over in the Eastern States who were investigating the control of cane toads

• The increase in knowledge of this topic

My one wish was that there was a larger variety of resources and studies