Download The Cane Toad

Invasive Biology:
The Cane Toad
• In many cases, a foreign species which was introduced to reduce or
eliminate a pest becomes a pest itself. As in the case of Cane toad
(Bufo marinus), reckless introduction has had a negative impact on
native fauna.
• The cane toad has changed many of the native environments
through different mechanisms such as interspecific competition,
consuming resources or by reducing the numbers of native
predators due to its high toxicity (Smith, 2005).
• Australia has been impacted the most by the invasion of the cane
toad, which was introduced to Queensland in 1935, as away to
eliminate agricultural pests (Phillips et al, 2006).
The Cane Toad
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Scientific name: Bufo marinus
Also known as Bufo toad or Giant toad
Native to Central and South America
Introduced to approximately 40 countries
However, introduction to the U.S. was accidental
Toads Worldwide
The Cane Toad
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Can weight up to 5.8 lbs
Adults can reach length of up to 15 inches
Females breed once a year, laying up to 30 thousand eggs
Eggs and tadpoles are toxic
Juvenile and adults have toxic skin
Toxins originate from the parotid glands, located posterior to the
eyes
• Amount of toxicity typically varies with size
The Cane Toad
• The surface of the
skin is dry and
warty
• They can vary in
coloration from
grey, brown, red
and olive
• Most active at
night
Cane Beetle
• The Cane Toad was introduced to control
sugar cane pests, such as the cane beetle
Toxicity
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Bufotenin is a chemical excreted by the Cane Toad
Can cause mild hallucinations
Lasts for less than an hour
Classified as a Class 1 drug in Australia
The practice of toad licking can lead to illness or death
Toad Licking
• Please DO
NOT try
this at
home!
Impact on the Ecosystem
• Devastate the natural ecosystem
– Voracious appetites
• Can consume up to 200 invertebrates in a single
meal
• It can also devour small mammals
• Remove more prey items form the ecosystem than
native frog species
– Compete with native species
Impact on the Ecosystem
• Kill native
species
– Toxins present
on skin kill
native
predators
– Toxic tadpoles
kill aquatic
predators
Invasion
• They were introduced to Queensland,
Australia in 1935
• Now they cover over 1 million square
kilometers
Australia
Effects on Native Species
• Some animals have adapted to the
presence of the Cane Toad
– Australian snakes
• Morphological Change
– Birds
• Hunting strategies
Beware!
• Toxins produced by Cane Toads can be
fatal to pets
Solutions
• There is no ONE specific method of
controlling the Cane Toad invasion
• Studies have shown that Cane Toads
prefer open space
• Therefore, adding barriers can effectively
slow down distribution
• Some people kill toads on site or…..
Make them into wallets and key
chains
The End
Bibliography
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Brown G.P., Phillips B.L., Webb J.K, Shine R. (2006) Toad on the road: Use of roads as dispersal corridors by
cane toads (Bufo marinus) at an invasion front in tropical Australia. Biological Conservation 1 3 3: 8 8 –9 4.
Greenlees M.J., Brown G.P., Webb J.K., Phillips B.L., Shine R. (2007) Do invasive cane toads (Chaunus marinus)
compete with Australian frogs (Cyclorana australis)? Austral Ecology 32: 900–907.
Phillips B.L., Brown G.P., Webb J.K., Shine R. (2006) Invasion and the evolution of speed in toads. Nature 439:
803.
Phillips B.L., Shine R. (2006) Adapting to an invasive species: Toxic can toads induce morphological change in
Australian snakes. PNAS 101: 17150-17155.
Phillips B.L., Shine R. (2006) Spatial and temporal variation in the morphology (and thus, predicted impact) of an
invasive species in Australia. Ecography 29: 205-212.
Smith K.G. (2005) Effects of nonindigenous tadpoles on native tadpoles in Florida: evidence of competition.
Biological Conservation 123: 433-441.