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“Now banned, the „bufiest‟ of Mexican waves!”

Cane toad and native Australian predatory fauna

related adaptations and behaviour.

„The long dry gut ache!‟

By Ian Browne-Shamrock News Darwin NT- Dec. 2006

(Revisited in Dec. 2013 via my home in Brunswick Heads NSW)

In 2006, I moved from the alternative lifestyle town of Nimbin

in subtropical northern New South Wales, and back to tropical

monsoon Darwin in the Top End of the Northern Territory to

teach in high schools. I left behind a creative valley community

where I was part of a team of folk, two of which were ex-ABC

radio hosts, where we made a community radio show each week.

Our slightly offbeat weekly radio show was played daily on a 24

hour loop in the US, and we also produced stand- alone radio

podcast documentaries related to the environment and politics.

None of this would have been possible without the input and

leadership of journalists and radio producers Warwick Fry and

Martin Jansen. Sourced: Drkarl.wordpress.com

Now alone, I decided to begin writing articles on invasive

species impacts to the Top End environment and Indigenous affairs stories. In

2007, I made my first of three trips to Borneo and an article I produced on

Sarawak was published in a newspaper in NSW. The other two trips to Borneo

saw me being invited into the underground movement in Malaysian Borneo to

„stick up‟ for the ecology and cultural groups of Sarawak. This saw the formation

of my story „The Kind Eyes of Sarawak‟, originally parked at

Blue King Brown‟s website, and its PowerPoint presentation

that have both travelled the globe. I then embarked on further

trips into SE Asia to develop stories on the ecological and

anthropological impacts related to development there. By now

I had a powerful group of Australian and international

journalists, and academics, supporting me in many ways, thus

my word on important social and environmental topics

travelled the globe unhindered.

So, my attention was drawn to the invasion of the cane toad

front that was sweeping across the tropical savannas and wetlands of the Northern

Territory and towards the small multicultural city of Darwin. I had in previous

times studied the impacts of the cane toad when I last lived in Darwin as an

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environmental science undergraduate at Charles Darwin University. I was

annoyed, as were many, with the NT Government and Federal Government, as

more should have been done to put in place environmental safe-guards to stop this

invasion. I set to task better understanding the ecological impacts of the cane toad

on the Top End environment and wrote an introduction essay (seen below from

page 7) – some of which had never seen the light of day until now, followed by

five smaller cane toad articles that were published in a popular NSW

newspaper, and which got about the place between 2006 and 2007 (as

seen within this folder). Thousands read these articles in Australia and

one was also kindly published by well known media personality Dr

Karl Kruszelnicki on his „Dr Karl.com‟ website.

Sourced: Frogwatch.org.au

The deranged title of this series was spawned in my laboratory of

neurons at a time when the „Mexican Wave‟ was being discussed

within the media as it was to be banned at cricket matches, and when

the „toad march‟, which moved west from Queensland and into the Northern

Territory, was also popular in the media.

There is information communicated within these articles on the findings of

scientists from two Australian universities. The University of Sydney‟s

Ben Philips, and Charles Darwin University‟s Tony Griffith’s knowledge

was welcomed. Both scientists give accounts as to information concerning the

adaptation of predatory Australian native fauna in relation to the aftermath of the

„long dry gut ache‟ derived from a feast of „the bufiest of illegal Mexican Waves‟-

the Neotropical Cane Toad, and the ecological resistance occurring in Australia‟s

tropical ecosystems to this introduced pest. Other scientists and eco-guardians‟

work has also been a much welcomed resource within my articles.

I also took part in a radio interview with journalist Warwick Fry by phone from

Darwin, down south into NSW, in relation to Australian soldiers „perhaps‟

finding cane toads in nearby East Timor, and the theoretical impacts this toad

species might have on Indonesian fauna. There are already native species of toads

occurring within this vast tropical archipelago, so the impacts would be perhaps

not so severe as compared to those occurring upon my originally „toad free‟

neighbouring continent. I swear the toad I saw in Bali, not far from the oceanside

Hindu temple Tanah Lot, was identical to the Central/South American

(Neotropical) species. To this day I am not sure whether cane toads arrived onto

Indonesian shores via Australia. Are they even there? Or is this warty

doppelganger just closely related in visual splendor, if not loitering within

ecological niche?

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Returning to Darwin in 2006

to the cane toad invasion!!

Since my five articles were published during the first decade of 2000, new

research has come to light pertaining to native frogs competing with cane toads

within the moist Australian landscapes, and the information is very interesting

indeed. Now living once again in northern NSW, Jan. 2014, it seems that the

fauna here, having had exposure to the invasive cane toad for far longer than the

fauna of the Northern Territory and WA Kimberley region, have somehow held

on. Perhaps not all species survived the cane toad invasion here in the subtropics,

but just the other day I saw a very large adult lace monitor, Australia‟s second

largest goanna species. I have seen many large monitor lizards over the years in

northern NSW. Last week a large green tree frog spooked me as I opened my mail

box. There are quite a few tree frogs around my place during the warm humid

months here in Bruns. The legs of one large, confident chap lay over my roof last

night in the languid, sultry evening air as the excitement of a storm approached.

They amuse me no end, and they too have survived the cane toad‟s arrival and

habitation of the east coast. In Darwin, my

brother had a resident tree frog that must have

had a few years to tell of as he was huge. He

had a large, protruding forehead and large red

eyes (Spring-healed Jack perhaps?) His house

mate was a rat, of all things, who sat at the

entrance to their rooftop hideaway each night

staring into those seductive red eyes.

The Ord River near Kununurra

In 2011, I was moving in towards the hot

tropical Kimberley town of Kununurra just

after sunset. After a long day‟s drive down into Western Australia from Darwin, I

was moving too fast to break as I entered a scene on the road near a creek which

included numerous cane toads and a large, light brown coloured snake. It was

either a King Brown snake, also known as a mulga snake, which is a black snake

cousin actually, or perhaps it was an olive python or water python. Sadly, I drove

over it, but was left wondering if it was intending to gulp down a few of the toads

nestled in about it. King Brown‟s have all but disappeared from the bush near

Darwin now, and my poor driving skills having nothing to do with this- I must

add. A few years back, cars were graced with a hand-held mirror at the NT/WA

border post to see if toads had hitched aboard the undercarriage of vehicles.

Nowadays, toads are to be seen everywhere in the western Kimberley. A goanna

breeding program is under way in the Kimberley as environmentalists are trying

to salvage what remains of the lizard populations and are trying to avoid the sharp

decline in lizard numbers occurring in the NT Top End.

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I arrived to Darwin once again in 2006, having been away in

NSW for a few years, to discover the cane toad‟s arrival to

places like my beloved Litchfield Park, which is a World

Heritage Listed national park that has brilliant monsoon

rainforest waterfalls with croc free and glass-clear waterholes;

34oc in temperature. It is also „storm heaven‟ and a very

exotic location to camp with good friends. I have taught

international tourists tropical ecology and snorkeling in these

uber-hot tropical paradises over the years and some of my

closest friends that I grew up with in Sydney also love this

place as much as I do. One thing that really saddened me was

the almost complete disappearance of the goannas from the

Top End picnic and camping sites. The Darwin region has the

highest diversity of monitor lizard species on the planet and

there was a group of very large, friendly goannas in Nightcliff, that used to cruise

about like domesticated animals along the foreshore in the front of unit

properties- looking out over the tidal zone in Darwin‟s northern suburbs. I never

did see them on my return to Darwin, but I managed to see the occasional smaller

goanna along Darwin‟s foreshore areas.

On the brilliant 2013 ABC TV series „Kakadu‟, well known Top End biologist Ian

Morris stated that goanna and snake species obliterated by the cane toad invasion

would not recover. I wonder? I did notice lesser numbers of Merten‟s water

monitors in Litchfield Park at one of the camp sites I frequent. They still remained

however, but in lesser numbers. In some aquatic sites inland from Darwin, I found

many toads, especially under the lights down in the tropical savannas of the

Katherine region where they competed with frogs, and both native and feral

geckoes, for abundant nocturnal invertebrate species during the hot sultry nights.

My Indigenous students actually dragged the cattle station‟s friendly resident

olive python out onto an oval from the scrub there. It measured 4m or more and

somehow survived the toad‟s appearance in the landscape. We were just taking a

look at the big python, no harm was done and he seemed

unfazed anyhow.

With a group of students from Darwin, I did a nighttime toad

muster in the southern Darwin outskirts near a large

waterhole. We found many scampering about that night. A

chef working at the resort there at the time of our visit

actually took a picture of a keelback snake, said to be

immune to the toad‟s poison, gorging itself on a cane toad.

His snap made it into the NT News, and a shy 3m olive

python had managed to hold on also which was a positive

sign. Yet, over the next six years closer to Darwin‟s town

centre itself, I only ever saw a couple of toads in any location during the wet

season nights. I always felt it a blessing to see frilled neck lizards in Darwin. They

actually snob–off the winter/ dry season daytime 31oc temperatures in Darwin,

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hibernating in the crowns of tall trees to await the more humid, broiling mid-

thirties coastal temps of the Build Up (from Sept. prior to monsoon). Sadly, their

numbers had also dropped with the toad‟s arrival.

As for the large green tree frog, Darwin‟s ultra humid monsoon season sees

literally thousands of these gentle souls croaking away through the warm wet

season nights, seemingly impervious to the cane toad invasion. One property near

where I lived in Nightcliff facilitated hundreds of them and their noise at night

was remarkable.

During Darwin‟s hottest period of the Build Up, Oct through to mid Dec, the

daytime max temps average 37oc in the inland rural regions and with

Singapore strength humidity!

Green tree frog

Sourced: Daily Mail.co.uk

Amphibian 'wimps'

The information below was sourced from BBC Nature by reporter Ella Davies, and was

kindly sent to me from friend, and well known environmental champion

Lil Williamson in Brisvegas.

Australia’s native frogs beat invasive toads

The frogs could be “Green Avengers” in the fight

against toad invaders

The tadpoles of Australia's native frogs can outcompete invasive toads, scientists say.

Toads evolve into super-invaders:

The toads are considered a threat to Australian wildlife, leading researchers to investigate methods to control their population. A study into competition between wild amphibian young revealed that the presence of green tree frogs reduced cane toad survival. Experts now suggest reintroducing the familiar frogs to suburban areas.

The results are published in the journal Austral Ecology.

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Non-native nightmares

They are now one of the International Union for the Conservation of Nature's (IUCN) top 100 invasive species and considered feral pests across north-eastern Australia. Their large clutches of eggs, ability to migrate 40km per year and poisonous defence are outlined as

some of the primary reasons for their population explosion. However, research by Professor Richard Shine and colleagues from the University of Sydney has highlighted the weaknesses of the animals in early stages of development. In 2011, the team reported that cane toad tadpoles cannibalise eggs to survive. Continuing research into this area, Prof Shine highlighted that despite this behaviour, cane

toad tadpoles are "wimps" when confronted with other species. Previous laboratory studies have suggested that tadpoles of the green tree frog Litoria caerulea have a particularly strong impact on the survival rate of cane toads. To fully understand the interactions between the two species in the field, Prof Shine and colleagues set up two temporary pools and studied how the frogs and toads developed. Observations revealed that toad tadpoles grew more slowly and spent longer as larvae when they faced competition.

Professor Richard Shine University of Sydney, Australia:- "If other larger tadpoles are present, the cane toad tadpoles don't get as much food - they can't compete successfully - and so they grow and develop slowly [and] often die as larvae," said Prof Shine. "Even if they manage to metamorphose - turn into small toads - they tend to do so at a smaller size, and we know that little toads are very unlikely to survive." Unlike many frog species, cane toads prefer to breed in disturbed waters but, according to Prof Shine, "there are several hardy city-dwelling native frog species that are happy to

breed in the same kinds of places as do toads" including the green tree frog. Averaging 10cm long and bright green in colour, L. caerulea is a well-recognised species in Australia where they are broadly distributed in western and northern areas down to coastal New South Wales. But conservationists have reported that the frogs have suffered from pollution in urban areas and some habitat loss due to expanding human settlements. In the study, the frogs did not prey on the tadpoles of cane toads and those that ate cane toad eggs were poisoned by the toxins they contain. However, the omnivorous frogs did compete for the

same food sources as the toads. Cane toad clutches contain thousands of eggs "So, if we can encourage native frog populations back into suburban areas where they once occurred, they will be able to reduce survival and recruitment of cane toads from those same ponds," explained Prof Shine. He told BBC Nature that he was "surprised by the consistency of the effects, and by how much the toads were troubled by the frog tadpoles". Overall, he was "delighted" with the

findings. "I think it's a great opportunity to involve school-kids [and] community groups in an action that will benefit local biodiversity - regardless of any effects on toads," he said. "I think that it would be terrific to have giant green frogs sitting in people's mailboxes again!"

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“Now banned, the „bufiest‟ of Mexican waves!”

Cane toad and native Australian predatory fauna related

adaptations and behaviour.

„The long dry gut ache!‟

By Ian Browne-Shamrock News (edited 2013/14).

“If they tasted nice, everyone would be taking a lick!”

Cane toad facts and fallacies:

Yes, they do look cuter stuffed, lacquered, placed in a top hat, and adorned with a

walking stick than leaping around the backyard like a randy bulldog with syphilis.

Yes, they were imported in the 20th

century from Central America to alleviate the

sugarcane beetle problem in Queensland, only, the warty blighters didn‟t actually

engage in the hunting strategies the tropical agricultural industry and pest

controllers anticipated. That‟s right, they didn‟t actually jump high enough to

snatch the beetles, they instead settled for anything native that came along closer

to gut „n‟ mouth level. “Great pre-release research hey!”

Rumors that Dame Edna Everage had a pet cane toad that spoke varying

dialects of Murrinh-patha, Jawoyn and Yolngu-matha have to date been

totally unfounded and recently proven untrue. It was, in fact, „Vincent‟, a

Rum Jungle (near Darwin NT) tree frog with a deranged anti-permeable

skin membrane fungal condition, formed after a romantic interlude with an

Indonesian House Gecko named Eloise on the west wall of the Rum

Jungle Roadhouse Tavern on a hot, sultry November evening, and whose

Top End slang and drawl had become somewhat deranged after his tongue

enlarged during a long night French kissing, whilst guzzling litres of his

favorite cocktail of 1960‟s DDT and Fiji‟s finest imported Kava ,

intercepted on its way to Arnhem Land.

Yes, they can squirt the toxic venom situated within the gland sacks found behind

their heads. A lady from Brisbane, who now resides in Darwin, told me how this

actually happened to her. Ironically, her partner was explaining this fact to

Aboriginal students in Katherine NT whilst holding a large toad, and was

subsequently hit in the eye by the poisonous projectile as well!

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Whacking the buggers with a heavy stick incurs the risk of the venom landing in

your eyes also. This practice has blinded at least one gentleman in Australia.

Antiseptic Detol stops them in their tracks, only I feel this is cruel. The freezer, or

a French beheading, probably a kinder way to euthanase these charming little

chaps. In Queensland during the 80‟s, during the era of Sir Joe. B. Petersen, many

„banana benders‟ decided that playing golf with these feral grub-munchers was a

worthwhile cultural experience. A sign of the times I feel.

Yes, some people in Queensland have in fact boiled a few toads to drink the slimy

concoction and to „trip-n-hallucinate‟ wildly. Some tripped so heavily that they

went all the way up to see Lucy in the Sky with Major Tom, and never came

back. So it seems that it isn‟t just the local feral ginger cat and nut-job rabbit that

might send you into the tickling, ominous kaleidoscopic tunnel and it is a very

dangerous, in fact „deadly‟ pastime.

So, is it addictive this toady venom? Well, ex-pat English friends living in

Coolum, on Queensland‟s Sunshine Coast where they hold cane toad races on

Australia Day, had a Doberman that frothed at the mouth and became a tad dizzy

after chewing on toads. She carried this out apparently unscaved quite a few

times. Some seem to enjoy it. Do you?

They are heading south along the coast towards Sydney and they have adapted to

growing longer legs in which to speed up their journey from the subtropics to the

warm temperate zone (Philips, 2006).

“Too cold for toads those winters of the „Sydney-A-climate‟ region you ask?”

Well, I have watched them huddle under stones and logs in both Nimbin and

Nashua; in subtropical northern NSW, awaiting the rain and warmth of spring.

They do hibernate where necessary, and in the Top End where the dry season

drought reduces toad mobility, they too hang loose by waterholes in wait of the

monsoon. They have since been sighted in the Sutherland Shire region of Sydney

where aquatic ecosystems exist.

No, you won‟t get warts from handling toads, but please remember that

the transportation of skin fungal and bacterial conditions to other

amphibian species may occur.

I seriously doubt that Richard Geer was actually successful in training a

cane toad to „dirty dance‟ to Beethoven, Blondie or Bronsky Beat on his

underground-cult thriller „Flight of the Jerbal-16‟!

Does the trail of destruction that the cane toad has left behind mean the inability

of native and endemic carnivorous species to „restock‟ in the wild?

“Well, read on and I will discuss this here.”

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Introduction

They don‟t have teeth and they have a different pectoral girdle structure compared to

frogs. No, I am not talking about Jabba the Hutt; I am in fact talking about Australia‟s

only toad species, one of the world‟s largest species of toad- the feral Bufo marinus from

the family Bufonidae, the true toads. The cane toad was introduced into Far Northern

Queensland in the 1930‟s and now resides as far south as central-coastal New South

Wales, and soon to be at wetland near you if you reside in Sydney, where I hope those

golden green bell frogs will up the rent on their luxurious wetland real estate.

A native of South and Central America, this Neotropical frog can now be described

perhaps as Pan Pacific as it was actually introduced into the Polynesian Islands, to also

deal with the South Pacific‟s sugarcane beetle problems, before arriving here. I first

encountered this crafty critter whilst on a couple of childhood holidays to Brunswick

Heads, subtropical coastal northern NSW (just south of the Queensland border). We

didn„t have toads hopping around the foreshore rocks of hometown Cronulla in southern

beachside Sydney in the 70‟s, so it was a curious sight indeed. In years to come I ran into

them once again and boy did they make their presence felt. It was 1978 in Fiji, at the Reef

Hotel, paradise indeed, except for the toads. Who ever invited them to our „Fijian hangi‟

that splendid sunset evening I‟ll never know, but it was an invasion, the ground was thick

with them. I was in Nimbin in northern NSW, in January of 2003, when a local man

(originally from England) ran from his house in the hills surrounding this alternative

lifestyle town; situated more than an hour‟s drive inland from the coast, to swat what he

believed was the first cane toad he had ever heard in the area. I moved to Nimbin a

couple of years later and many were to be seen in the

warmer months there jumping up against my wooden

veranda, nabbing insects under the porch light. In fact,

before moving to Nimbin, I lived in Nashua on a

rainforest property 25 minutes drive from coastal

Byron Bay, and as the drought loosened its grip on the

region, I noticed not only the toads‟ numbers

increasing, but too the size of these amphibians.

Nimbin Rocks, a sacred Bundjalung site

Discussion

Preempting a toad strike in Australia’s tropical north?

Whilst I was studying at Charles Darwin University, a national parks ranger described

how he believed the cane toad made its way across the Gulf of Carpentaria in Qld. He

explained how they could have used the mangrove communities in which to move in the

hot sunny conditions, as the salt water would not have deterred them, as their Latin

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species-name „marinus’ possibly suggests. Many toads also used the cow troughs to wait-

out the semi-arid land‟s daylight hours, as they dehydrate quickly under a hot sun. Little

was done to stop the advance of the cane toad into the tropical monsoon wetlands of the

Northern Territory, this was said to have influenced the sacking of the then head of NT

Parks, who believed the environmental impact of a toad invasion would be minimal, and

public outcry was boisterously instigated at such inaction when the warty, bugling-

evening onslaught occurred, as this invasive species moved closer to Darwin- the

Territory‟s capital and largest town.

How did the quolls fare?

Northern quoll Sourced: Gibbriverroad.net

Frog-call recording stations were positioned in areas of Kakadu, a

famous NT World Heritage Listed national park, as a surveillance

measure to alert rangers and the government of the toads‟ arrival

into ecologically sensitive areas. The rangers‟ bikes actually

triggered off the recording sensors, sounding like a large Bufo

marinus. But „hats off‟ to more recent management practices

where native northern quolls, a predatory marsupial, who would

have preyed upon the toads, were relocated from areas of the

mainland Top End to offshore islands in the north, such as the

English Company Islands on the Gove Peninsular, as a safeguard

against quoll extinctions. Removing the quolls would have ecological flow on effects

such as „theoretically‟ allowing rare partridge pigeons to increase in numbers where quoll

predation impacts would be lessened. However, the summer monsoon quite literally

rained upon the parade as storm debris, such as floating logs with cane toads aboard,

washed from swollen river mouths and out to these island refuges. A cruel reckoning

indeed, but this mustn‟t hamper native fauna protection measures, particularly when

goanna numbers have been noticeably decreasing from areas such as Katherine Gorge,

and barramundi have been seen floating belly-up in Koolpin Gorge, whilst the humming

bugle of a cane toad is heard from the reeds along the creek banks.

But could they have stopped the toad invasion in its tracks anyhow, this Mexican wave

of ill repute? Probably not, as University of Sydney biologist Ben Philips believes that

trying to trap these invasive toads would be like trying to find a needle in a haystack in

the overall population management impact (ABC Stateline, 2006). Famous Australian

author Tim Winton, and fellow Western Australian eco-lovers, have been rallying to try

and prevent the toad invasion from inside the NT border marching into the Kimberley

region. Folk from the NT‟s „FrogWatch‟ have been proud of their efforts in trapping

toads and describe the stable goanna population along Darwin‟s foreshore proof of such

success. The Top End is actually the world‟s hot spot for the Veranidae family; the

monitor lizards, so this toad march has got many lizard loving scientists nervous.

Katherine resident Paul Baker won the Northern Territory Government‟s „Great Cane

Toad Trap‟ competition. He caught 112 toads in one trap! Insects are attracted to lights,

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which then lure the toads up a ramp and into incarceration. The toads fall through a

trapdoor into a box and cannot escape. You can also purchase cane toad traps from the

FrogWatch website >www.frogwatch.org.au<. One field trap caught 453 cane toads in

six weeks (CRC Aust.Savanna Links, 2005).

An historical blunder in pest management research Could a native species control the cane beetle?

A thought occurred to me whilst I was researching this story for you, if sugarcane is a

native of our closest neighbour Papua New Guinea, then why didn‟t the agricultural

industry, scientists and pest controllers invest in localised research to discover a

Melanesian hero? Perhaps they did? And as Australia is actually connected to the island

of New Guinea; we are Australasia remember- the Torres Strait Islands are the drowned

mountain tops of the land bridge to Papua New Guinea from northern Qld, then perhaps

there are subspecies of the predators of cane beetles- or other sugarcane munching fauna

residing here already. We share many fauna and flora species with New Guinea, the

waters off New Guinea too deep to be heavily „trans-populated‟ by Southeast Asian

fauna, except a few aerial voyaging mammals, birds, and humans of course. Thus, you

might be asking yourself; “why didn‟t these native heroes march forward and make a

feast of the cane beetle?” Well, maybe the sugarcane was planted out in large areas too

fast for the native cane beetle controller to be effective in the short term. And perhaps the

introduction of the cane toad in turn meant a feast upon the native cane beetle controllers,

thus a lack of visible native control to this day. I am surprised that whatever was deemed

successful in controlling cane pests in the West Indies, where introduced Papuan

sugarcane also occurred, this pest management technique would have held some answers

at the time. I am surprised that the toads in the islands off South America and Central

America didn‟t communicate their lack of interest in jumping an extra foot into the air.

They could have saved us all the nauseous gut ache and financial headache, but Polynesia

and Australia are just another paradise for the

toads to plunder I guess.

The dingo, the terrestrial apex predator in Australia, is

an Asiatic wolf that was introduced into Australia by

Asian seafarers at least 5000 years ago; outcompeting

the Tasmanian devil and thylacine for food and habitat

on the mainland Photo sourced: Flickr.com

Anyway, the research in those heady, naive days

of the early-mid 20th

Century didn‟t really allow for the colonization time, the

demographics, and the negative impacts inflicted upon other species, such as the native

competitors and prey species that also fall into the introduced species‟ ecological niche,

to be taken into account. You only have to sing the invasion song of the feral goat, pig,

cat, dog, camel, buffalo, donkey, rabbit, European red fox, prickly pear cacti, lantana,

camphor laurel, bitou bush, parra grass and Mimosa pigra to understand what I am

communicating here, along with my ancestors from „Ol Blighty‟- the instigators of these

nightmares. There was a lack of the understanding of the establishment strengths,

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environmental tolerances and lag time periods associated with an introduced species‟

subtle colonization before it explodes into highly invasive, unmanageable, potentially

destructive populations. The adaptation of information concerning an organism‟s life

history traits, and population biology-demographics moulded into scientific modeling for

a release program of exotics into Australia, was also at infancy stages in research. Many

introduced species nowadays are not released for at least eight years as studies of their

ecological impact effects researched via CSIRO, for example, occur. This includes not

only the introduced species‟ environmental impacts, and the information of their

biological traits, but also the important research related to an ecosystem‟s tolerance to an

introduced species, and also how the recipient environment in turn affects the degree of

invasiveness of an introduced species (Sakai and Allendorf et al. 2002).

Impacts on large lizard species in the Northern Territory Varanus panoptes

Once a very common sight in the Top End Photo sourced: dwpicture.com.au

In 2002, I spoke with biologist Anthony Griffiths at

Charles Darwin University about the ecological

impacts the toads would pose for the Top End

environment. Prior to my conversation with Tony, he

had a communicated this information to a reptile

magazine also. He believed that many species of

lizards would in fact adapt to the toads after initially

declining in population. Tony believed that not all lizards such as goannas species would

actually die out, some would either disagree with the „sickening‟ taste, and live to see

another day, or perhaps they wouldn‟t like the look of this invader and not even bother

with the toad at all. Around the same time I spoke to Tony, the ABC TV documentary

„From the Heart‟ revealed ranger Greg Miles‟s and his biologist friend Ian Morris‟s

theories about the impacts from the toad invasion on native aquatic species. I had also

spoken to Greg Miles in 2001 about the impacts on toads in Kakadu, and both of these

men feared that the toad would all but wipe out Merten‟s water monitor, as they believed

this had already happened in parts of tropical Queensland (See my 4th

cane toad article on

monitor lizards). I can happily say that after a few years away

from Litchfield Park near Darwin, I returned recently to see the

resident Buely Rock Hole and Wangi Falls Merten‟s water

monitors still alive and well there, and no sign of the cane

toads „as yet‟ (They have since invaded the region and reduced

lizard numbers). I am also very pleased to say that Anthony

Griffiths has willingly agreed to a radio interview with me in

the New Year relating to information on a paper he has been

writing on the impacts of cane toads in the Kakadu region.

Tony also explained to me in greater detail than I had attained

about the research Ben Philips had been collecting in NSW

and the NT, with the University of Sydney. This has helped me

shape the following information as Tony elaborated some of Ben‟s findings with me.

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Cane Toad impacts on snake species

in the Northern Territory I had described to Anthony Griffiths about the theories I had heard of over the years in

relation to red belly black snake numbers falling in the moist, subtropical areas of coastal

NSW due to their predation of cane toads. Many people believed that eastern brown

snake numbers had in turn increased as there was less predation upon juvenile brown

snakes via the black snakes. Tony suggested that theories are one thing; speculative, and

that scientific research is required to practice and „try and prove‟, or disprove, a

hypothesis. I had also heard that snake „head size‟ correlated to survival of some species

of snakes, as the smaller the snake‟s head the less able the snake was to prey upon a toad.

With my own scientific training I at least hypothesized to the teller of this theory that

some species of snakes have differences in head sizes between males and females, and

that perhaps a certain species such as the red belly black snake had a relatively small head

to begin with, thus bettering its survival chances amongst a paradise of swampy, toady

delights.

Poisonous but passive,

the red belly black snake Photo sourced: Flickr.com

But what of smaller toads, they are poisonous too

aren‟t they?..I also suggested. I had lost a mating

season visitor, passive 2.5m carpet python-„Fats

Domino‟ in Nashua NSW, due to what I believed

was a poisoned rat or cane toad. She used to breed with my male resident rainforest cabin

dweller – a friendly 2m „Neil Diamond‟…ignore the titles, Fats‟ was definitely female.

Tony told me that it was actually Ben Philip‟s research that suggested that „brown

snakes‟ with smaller heads had actually been naturally selected for due to the

environmental pressures associated with cane toad predation, an evolutionary phase

happening right now in our bush. Ben Philips has also observed how cane toads have

become a larger animal, increasing their leg span and pace as they move further south

into the temperate zones. This is also true for toads heading west from NT/Qld and into

the Kimberley. I was out at Fogg Dam, also near Darwin, in December 2006. This easily

approached tropical paradise, rich in avian diversity, is not only a location which is one

of the highest cloud-to-ground lightning-strike zones on the planet; but the region also

has the largest predatory vertebrate biomass on Earth. Or perhaps it once did? I only saw

one dead cane toad and thankfully no live ones; come dark I‟m sure this would change. I

did see a very large goanna, which made me happy, as I had seen one there also in the

abutting monsoon rainforest ten years previous when I first visited this then, „cane toad

free‟ tropical wetland ecosystem.

(On subsequent visits to Fogg Dam I didn‟t see any goannas)

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I am not sure if anyone has allocated needy capital to stablising threatened species

populations, such as goanna species in captive breeding programs for later release to the

wild? (They have since) Perhaps the following information will provide you with such

notions also? Ben Philips has been studying the impacts of cane toads in places in the

Top End including Fogg Dam and suggests that in some places there has been a reduction

in as much as 95% of goanna numbers (ABC Stateline, 2006). He explained how only

resistant and non-cane toad predating individuals are surviving in these regions (ABC

Stateline, 2006). Once bitten twice shy perhaps or at least left with a vile taste in the

mouth and a roaring headache. Philips believes that as many as 75% of the planingale

population (a small carnivorous marsupial), will survive, as they have proven to be quick

learners (ABC Stateline, 2006). As for snakes such as the death adder, only 30 percent

will survive, however, in the long term Philips believes that the cane toads will not be

such a problem as there will be enough genetic diversity available in the wild for

populations of the adapted predatory species to survive and hopefully flourish in the long

term (ABC Stateline, 2006). But when is this „long term‟ forecast you might be asking?

Well, Ben Philips believes that in around 100 year‟s time numbers of species; such as

goannas and death adders, will be relatively stable (ABC

Stateline, 2006). This means that a couple of generations of

Australians will possibly go without the charms of

commonly seeing a large, cheeky goanna cruising around

the picnic ground I feel, and as for the death adder, well it

too has a right to survive on its own land surely.

The death adder Sourced: Deadlyaustralians.com

Now, there are two theories at play here in relation to the red belly black snake and cane

toad relationship in the wetter environments along the east coast of Australia. Ben Philips

has been researching this predator to prey relationship. One theory is that the black

snakes, a relative of the cobra, have had toads on offer in some areas over time and have

learnt not to eat them any more. The other theory is that in areas where newly arrived

toads have been recorded, only half the black snakes ate the toads, the other half

seemingly resisted. Further analysis of such worthy hypothesis described and researched

by Ben Philips, is that not only do some goannas and snakes reframe from eating the cane

toads; they are actually genetically predisposed to this action. The brown snakes

obviously weren‟t in their study area I feel. The second is that many taste and „spit out‟

the putrid toad; „conditioned behavior‟ from experience, and never attempt to eat one

again, thus living a better, healthier existence. Tis a bit like a health conscious person

trying fast food again after many years of going without and deciding to bin the greasy

substances rather than finishing the feast.

In conclusion to such important research carried out by the likes of Ben

Philips, is that there is some hope at the end of the croaking invasive rainbow, but more

research and perhaps a helping hand in population management is needed I feel. I look

forward to sharing with you Tony Griffith‟s information next year and we can then also

15

entertain the facts and follies of predator to prey relationships occurring in Australia in

relation to invasive species such as the cane toad. I am just waiting for someone to further

explain to me the factual certainties related to ravens, crows and kookaburra‟s predation

and feeding behaviours when it comes to dining with the Toad of Toad Hall? Do these

intelligent birds in fact flip the toads onto their backs and bypass the poison glands in the

process? I am sure many more facts and follies will be created as this „banned, bufiest of

Mexican waves‟ continues to sweep across our moist, warm landscapes.

(The following five articles explore some of these mysteries)

References

Thanks to Anthony Griffiths at Charles Darwin University for giving up his time to help

me better understand some of the ecological relationships mentioned within this essay

and for providing me with his own cane toad knowledge.

Australian Broadcasting Commission Television, 2006. Territory Stateline- Interview

with Ben Philips.

Cooperative Research Centre for Tropical Savannas Management, Savanna Links, Issue

31. Jan-June 2005.

Sakai A.K., Allendorf F.W., Holt J.S., Lodge D.M., Molofsky J., With K.A., Baughman

S., Cabin R.J., Cohen J.E., Ellstrand N.C., McCauley D.E., O‟Neil P., Parker I.M.,

Thompson J.N. and Weller S.G. (2001). The population biology of invasive species. Ann.

Rev. Ecol. Syst. 32:305-32.

Special Thanks to Anthony Griffiths,

Lil Williamson, Dr Karl Kruszelnicki @drkarl.com, Warwick Fry @ NIM FM, Bob Dooly @ The Nimbin

Good Times, and Cherylanne Hughes for vandalizing and

plastering my work space „yet again‟ in cane toad

-paraphernalia for the drkarl.com article.