Education - a short run down on whether Cane Toads are a saviour or a menace. It begins with five, maybe, known facts and why they were introduced to northern Queensland. And now 85 years later do they hold Australian Species at ransom?
2. Exterior view of the pond and cage in Gordonvale, QLD constructed for reception and
breeding of 101 cane toads from Hawaii. Virtually all cane toads in Australia today are the
descendants of these cane toads.
Source: Queensland Historical Atlas.
9. Common Name: Cane Toad
Scientific Name: Rhinella marina (also known as bufo marinus)
Type: Amphibians* (cold-blooded)
Diet: Omnivore*
Group Name: ‘A knot of toads’ or ‘A nest of toads’
Average life span in the wild: five (5) to ten (10) years
Size: 10–15 cm (4–6 in), with a maximum of 24 cm (9.4 in)
Weight: up to 1.8kg (4Ibs)
Amphibians
Amphibians are small vertebrates* that need water, or a moist environment, to survive.
Omnimore
An omnivore is an animal that has the ability to eat and survive on both plant and animal matter.
Vertebrates
Having a backbone; spine.
10. In July of 1935, the Queensland Government introduced the CANE TOAD into Australia as
part of an effort to curb the CANE BEETLE (Dermolepida albohirtum) and the FRENCH’S
CANEGRUB (Lepidiota frenchi) which were eating away at the sugar cane crops – their
‘whitegrub’ larvae eats the roots of sugar cane and kills or stunts the plants.
The Australian Bureau of Sugar Experimental Stations imported about 100 toads from Hawaii
to the Meringa Experimental Station near Cairns. They bred quickly and more than 3000
were released in the sugar cane plantations of north Queensland.
The experiment was ineffective, but the CANE TOAD adapted well to the Australian
environment and quickly spread over the next decades. It is estimated that the CANE TOAD
migrated at an average of 40kms (25 miles) per year.
They can be found in Queensland, New South Wales, the Northern Territory and Western
Australia.
Note: 1935 – this was before the use of agricultural chemicals became widespread.
Dermolepida albohirtum
Cane Beetle
Lepidiota frenchi - French’s Canegrub
11. Cane Toads are voracious* feeders.
They can dramatically reduce populations of native:
• Frogs,
• reptiles, and
• Other small creatures.
Their skin contains toxic venom* that can also kill
native predators*.
Note:
Although the Cane Toad is regarded as undesirable, it is not a
prohibited or restricted invasive animal under The Biosecurity
Act 2014.
Predator
An animal that naturally preys on others.
Venom
A substance (poisonous) injected into prey by biting or stinging.
Voracious
Wanting or devouring great quantities of food.
Animated map showing the spread of the Cane Toad
(Rhinella Marina or Bufo marinus) throughout Australia
from 1939 to 1980 at five year intervals.
Map: Froggydarb, Mediawiki Commons
12. Since their introduction to Australia (north
Queensland) the CANE TOAD has expanded through
Australia’s northern landscape and has been moving
westward at an estimated 40 to 60km per year.
Their introduction to Australia was ineffective at
controlling pests. Cane Toads were officially declared
a pest species themselves in Western Australia in 1950
– even though they hadn’t made their way there yet.
The Cane Toad reached:
• Brisbane by 1945.
• Burketown (north-western Queensland) by the early 1980’s.
• Iron Range (Cape York Peninsula) by 1983.
• Cape York (tip) 1994.
• Roper River (Gulf of Carpentaria in the Northern Territory) by 1995.
• Kakadu National Park by March 2001.
• February 2009 – they crossed the Western Australian border over 2000km from the site
they were released 74 year before (1935).
• Byron Bay (to the South) in 1965.
• Yamba and Port Macquarie (north coast of NSW) in 2003.
Cane Toad Eggs
13. Ecology
Cane toads search widely (forage) at night.
The cane toad is a ground-dwelling predator, primarily eating terrestrial* and aquatic
insects* and snails.
The cane toad will even eat food left out for pets.
The cane toad can accidently be transported from one place to the other; in a car over the
border – they could be in pot plants; on loads of timber; hitch-hiking on your belongings.
Cane toads need constant access to moisture to survive.
Instead of drinking, they absorb water through the skin on their belly from dew, most sand
or any other moist material – but if they are forced to stay in flooded conditions they can
absorb too much moisture/water and die.
They can also die in dry conditions. (water/moisture loss)
Note: In Australia there are no specific predators or diseases that control cane toads.
The females can lay between 8,000-30,000 eggs at a time.
Eggs hatch in two or three days.
Tadpole stage lasts between four (4) and eight (8) weeks.
In Tropical conditions adult size is reached in a year; in colder climates may take twice as
long.
Aquatic insects
a group of insects especially unique because they spend at least part of their lives in water.
Terrestrial insects
include ants, flies, crickets, grasshoppers and spiders.
14. Impact
The cane toad defends itself through POISON and is POISONOUS (this can be in varying
degrees).
Ingesting a cane toad means that ‘that predator’ will die rapidly.
“Here is an animal that is dangerous not because of what it eats but what happens
if something else eats it. And along with their poison it’s the cane toad’s ability to
cover ground that makes them such a massive threat.”
From the Video:
Invasive Cane Toads Are Threatening Australia's Native Wildlife | Jeremy Wade's Dark Waters
• Cane toads contain poisons that act on the heart and on the central nervous system.
• The poison is absorbed through body tissues such as those of the eyes, mouth and
nose.
• Cane toads poison and kill anything that consumes them.
• Cane toads also transmit diseases including salmonella.
• Cane toads displace and out-compete native species for food and resources.
Cane Toad Tadpole
15. Control
Can cane toads be controlled?
At the local level yes – by:
Collecting the cane toad eggs from the local creeks or ponds or by humanely disposing of the
adult cane toads.
Control is best at the egg or adult stages – why?
As cane toad tadpoles can be confused with some native tadpoles.
Adult cane toads can also be confused with some of the larger native frogs.
You need to know the difference between A FROG and A TOAD and in your local area
the LOCAL FROG FAUNA and your CANE TOAD. (see next slide)
Cane Toads cause devastation but there is a slight silver lining – in some cases native
fauna/species are adapting to the presence of cane toads and recovering from the impact of
their “insertion”.
What is the most humane way to kill a cane toad?
Fauna
the animals of a particular region, habitat, or geological period.
Flora
the plants of a particular region, habitat, or geological period.
17. Webography
The rapid spread of Australia's cane toad pests
https://www.bbc.com/news/world-australia-39348313
CANE TOAD
https://australianmuseum.net.au/learn/animals/frogs/cane-
toad/?gclid=EAIaIQobChMIm9qi6eP16AIVx30rCh2WzQ2EEAAYASAAEgJRhvD_BwE
10 FACTS ABOUT CANE TOADS
https://www.wwf.org.au/news/blogs/10-facts-about-cane-toads#gs.3x5xw6
Cane Toads (Brisbane City Council)
https://www.brisbane.qld.gov.au/clean-and-green/natural-environment-and-water/biodiversity-in-brisbane/wildlife-in-
brisbane/pest-animals-and-invasive-species/cane-toads
Business Queensland
https://www.business.qld.gov.au/industries/farms-fishing-forestry/agriculture/land-management/health-pests-weeds-
diseases/pests/invasive-animals/other/cane-toad
Difference between FROG and TOAD
https://www.wikihow.com/Tell-the-Difference-Between-a-Frog-and-a-Toad
Cane toads found in central Canberra could pose risk to pets, ACT Government says
https://www.abc.net.au/news/2018-10-16/cane-toads-found-in-canberra-could-pose-risk-to-pets/10382340
18. Study the Maps in the next few slides.
Answer the following for each Map (Figure)
Figure 1:
1. The data represented in Figure 1 is sourced from where?
2. The ‘electric green’ colour identifies what type of information?
Figure 2:
Look at Figure 2. Cane toads have and continue to spread across Australia. In which states have they spread?
Figure 3 and Figure 4:
1. What information is represented in Figure 3?
2. The temperature in which states is not suitable for cane toads?
3. What would you surmise about the cane toad occurrence in Australia, by studying Figure 3.
4. What is the difference between Figure 3 and Figure 4?
5. In a sentence (or two), what data is represented in Figure 4.
6. What would you surmise about the cane toad occurrence in Australia, by studying Figure 4.
7. There is a correlation (a co-dependency) between Figure 3 and Figure 4 in explaining the occurrences
of the cane toad in certain parts of Australia between 1935 and 2017.
Study Figure 3 and Figure 4. What is this correlation (or co-dependency)?
Figure 5
Study Figure 5.
1. What information is presented in Figure 5?
2. Why are cane toads limited to the northern part of Australia?
3. Towards the south of Australia cane toads are able to survive along some coastal regions, why is this
so?
4. As we go further south of Australia, cane toads seem to have reached their limit of potential range,
how do you explain this?
19. Figure 1:
Data source: Atlas of Living Australia, Department of Agriculture and Fisheries