A new weapon in the war on invasive toads
[Music]
cane toads
are relentless invaders
native to central america cane toads
were transported
to sugar cane growing regions of the
world early last century
in the hope they would eat and eradicate
beetles that were devastating sugarcane
crops
this cane toad experiment held the
promise
of a cheap permanent and
everlasting solution to a commercial
problem
the experiment failed spectacularly
cane toads showed no interest in the
beatles
whatsoever instead
they launched a global invasion of
epic proportion cane toads reproduce
at an astonishing rate they eat
just about everything and they are
highly poisonous
across all life stages eggs
tadpoles adults poisoning and killing
virtually every potential predator
the release of just 100 adult cane toads
in australia
a mere 80 years ago led to the current
situation
where hundreds of millions
of poisonous toads now occupy
millions of square kilometres of
australia devastating
native species as they advance across
the nation
cane toads poison and kill lizards
even large goannas they even kill
crocodiles
cane toads poison and kill snakes
including some of the most venomous in
the animal kingdom
even top tier predators are not immune
to cane toads
cane toads poison and kill furry native
species
such as the northern australian qual and
other furry friends
like dogs and cats
for many years the only option
for controlling cane toad numbers was to
hand capture
of adult toads known as toad busting
despite dispatching many tens of
thousands of adult toads
toad busting alone is not the answer
each new generation of toad replenishes
and builds on the last and the invasion
continues
unabated in 2010
time magazine placed the cane toad in
the top
three invasive species in the world
cane toads truly are the borg of the
animal kingdom
and unfortunately at times it seems as
if
resistance is futile we set out
to develop a new cane toad control
solution
inspired by nature and capable of
operating
in parallel with toad busting
we targeted a cane toad life stage
that had previously been deemed
untouchable
the tadpole cane toad tadpoles are
highly distinctive
and easy to spot emerging as black
swarms of many thousands in the shallows
creeks dams and backyard ponds when the
weather
is wet and warm when it comes to finding
cane toad tadpoles we know
exactly when and where to look
and what to look for that toad tadpoles
had not been targeted previously
due to the fact that they are almost
impossible to catch by hand
they’re far too many and they are far
too agile
any attempt at hand netting risks
disturbing
fragile aquatic ecosystems and harming
native species some 2500 years ago
a chinese general wrote the supreme
art of war is to subdue the enemy
without fighting
sound advice if
only we could subbu
subdue towed tadpoles without fighting
and without turning fragile aquatic
ecosystems into battlefields
but how ecologists had observed
that cane-toed tadpoles can
hunt and eat the eggs of other female
toads
there’s a number of possible reasons for
this
tadpoles may be hungry and the eggs are
a nutritious snack
the tadpoles may be staking a
territorial claim
by eliminating genetic competition
or the tadpoles could be repurposing
the poison of the eggs to their own
benefit
more importantly it was also observed
that toad tadpoles successfully hunt
even in murky water with zero visibility
regardless of why tadpoles eat eggs
the more important question was how do
tadpoles find eggs they can’t even see
we discovered that toad padpoles
are drawn to a chemical attractant that
is released
by toad eggs we isolated
and identified this attractant this was
a eureka moment
but before we could use the attractant
to control tadpole behavior
to our advantage we first had to
dramatically increase our supplies
we knew we could extract the attractant
from dead adult toads but we would need
a whole lot of dead toads the call went
out
our bring out your dead appeal
worked and we received
hundreds then thousands of dead
toad busted toads these were processed
in our lab
using an approach that was part csi part
survivor
and part myth busters
put simply we used a giant stainless
steel
blender
to make toad smoothies
from which we extracted large amounts of
tadpole attractant
next we needed a way to deliver the
attractant
the local pet store provided the answer
in the form of air stones
small porous stones about the size of a
dice
once painted with attractant these
stones became
tadpole baits or what we like to call
bufo tabs
finally we went to the local hardware
store
to buy the materials to build a basic
funnel trap
these consist of a simple plastic box
with two plastic funnels inserted and
glued
into opposite ends funnel traps are
cheap
and easy to make we were ready our
theory was
if we placed a bufo tab in a funnel trap
near a swarm of tadpoles the tadpoles
would detect
and follow the attractants sent into the
trap
the theory worked when placed in the
shallows
where tadpoles congregate a single bufo
tab
in a funnel trap attracted and trapped
several thousand poisonous towed
tadpoles
in a couple of hours
as a bonus the attractant is highly
specific
to towed tadpoles and doesn’t attract
frog tadpoles
once trapped the toad tadpoles could be
harvested
humanely euthanized and disposed of
safely
to take the battle to the toad we
created
the cane toad challenge a not-for-profit
community engagement and citizen science
initiative
we provide free baits
and teach the public how to make and use
their own traps
it’s early days but our tadpole trappers
have already removed over a million
poisonous towed tadpoles from local
waterways
we may have started locally but our plan
is to go national
and then global so
join us trap tadpoles
and turn back the toad invasion thank
you
you