Aiden
Cane toad as a model invasive species
This table below summarises the qualities of a
species which lead it to become invasive.
Essentially most of the problems which are
caused by invasive species result from changes
to the delicate balance of inter-related species
in food webs.
Study the table, watch the two short videos on
the Inthinking Invasive species page
Qualities of invasive species
Alien species have few natural predators.
Alien Species have rapid growth, high reproductive
rates
Aliens out-compete and displace native species.
Alien species dominate an ecosystem, change food
webs and reduce biodiversity
Alien species dominate an ecosystem and cause
physical damage
Alien species have an ability to tolerate a wide
range of environmental conditions
Cane toad
(Rhinella marina )
The poison it secretes from its glands kills
predators reducing predation.
Females lay thousands of eggs twice a year
Native frogs only breed once per year.
Predatory monitor lizards, eat cane toads and
die resulting in an increase in one of the lizards'
typical prey, the crimson finches.
Huge numbers are found at times of the year in
Australian towns.
The cane toad has survived the Australian dry
season and is known to swim well, and walk
long distances at night.
Questions
1. Which of the qualities in the table would help it to be a successful biological control?
outAliens
………………………………………………………………………………………………………………………………………………..
caupereantdisplaae nativespeciess
2. What would the cane toad toxin do to native Australian animal preditors, like snakes.
predatars
The foxinkills
………………………………………………………………………………………………………………………………………………..
3. Why were cane toads brought to Australia in 1935?
to
Theyareintroduced
pest
dill
beetless
………………………………………………………………………………………………………………………………………………..
4. A hundred toads were introduced; how many toads are in Australia now?
About 200 millial toads
………………………………………………………………………………………………………………………………………………..
© David Faure, InThinking www.thinkib.net/biology
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Cane toad as a model invasive species
5. What is the key to the success of the cane toad? Why did they become an invasive species?
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,
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,
6. Why does this give the Cane toad an advantage over native species?
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isalarger populatiau f
rapidlyas
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than
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cale
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7. What problems can cane toads cause for domestic animals, cat’s and dogs?
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………………………………………………………………………………………………………………………………………………..
They May
8. What effects would the arrival of cane toads have on native frogs?
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frngs
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………………………………………………………………………………………………………………………………………………..
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9. What effects have cane toads had on higher predator populations?
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………………………………………………………………………………………………………………………………………………..
Tey
………………………………………………………………………………………………………………………………………………..
10. What is the most effective localised method of reducing cane toad populations, explain you
answer?
Use au exclusin fencl to stop cane toads
into the wafe
………………………………………………………………………………………………………………………………………………..
qexting
lay egy fheponf
sourae as caretoads
n
………………………………………………………………………………………………………………………………………………..
© David Faure, InThinking www.thinkib.net/biology
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