This morning at breakfast, Vilis told me, “Last night, I killed a cockroach in the living room.” I asked him how big it was, so he indicated a length of about three inches and told me, “They’re really fast.” Well, I can’t say Richard didn’t warn us.
We decided to open the new year with a drive up Castle Hill to enjoy the view out over Townsville and ocean, followed by a stroll along The Strand, the city’s ocean-front park. I navigated for Vilis, directing him north out of Railway Estate toward downtown, and then west to the northern slope of Castle Hill, a monolith of pink granite that mounds upward in steep slopes from the south and falls away in sheer cliffs to the north. Observing several people walking up the road, we parked the car and followed the steep, winding pavement on foot, stepping over several huge toads squashed by vehicle tires.
The squashed toads could only be cane toads, Rhinella (Bufo) marina, the central characters in one of Australia’s numerous tales of species introduction gone terribly wrong. More than 3000 of the toads, which are native to the Americas, were set loose in sugarcane fields in North Queensland in 1935 in an attempt to control two species of cane beetles.1,2 Once released, however, the hefty toads, which can reach a quarter metre in length and weigh up to 2.5 kilograms, proved completely ineffective at controlling the target species because they couldn’t heave themselves high enough into the air to catch the beetles, nor could they climb well enough to scale the canes in search of prey.1 So, cane growers were left with not only the pesky beetles, but with more than 3000 very large toads that excelled in three capacities: 1) producing highly poisonous bufotoxin in glands behind their eyes and on their backs, 2) eating voraciously, and 3) breeding prolifically at any time of the year.2
That was a recipe for an ecological disaster, which has since transpired. Not only do the toads now compete with native vertebrates for prey such as insects, frogs, small reptiles, mammals, and birds, they are also highly toxic when consumed and may cause death when eaten by native animals, as well as by pets.1,2 Freshwater crocodiles, egrets, snakes, frogs, fish, goannas (monitor lizards), and northern quolls (spotted marsupial carnivores the size of a large kitten) are particularly affected by ingesting the poisonous toads, which have spread southward and westward in Queensland, as well as beyond its borders.1,2
But Australia is fighting back, perhaps most creatively through the instigation of annual toad-capturing events in several northern cities. Townsville hosted its first Toad’s Day Out in March of 2009 and hauled in over 362 kilograms of cane toads, all of which were captured alive and unhurt by residents, and then killed humanely by city workers.3 More than 400 people – old and young – caught over 3600 toads, the largest of which weighed 556 grams and was nicknamed ‘Bigfoot’ by his captor, a young fellow who’d observed Bigfoot munching down dog food on the back porch before nabbing him.3
Drizzle spit moisture onto us as we continued upward toward the summit of Castle Hill, passing pink granite boulders, road cuts of orange soil, and scattered trees and shrubs. Much of the vegetation looked battered by the lengthy dry season, with brown leaves drooping from branches, shrubs completely bare of leaves, black evidence of fire (prescribed burn), and desiccated grasses forming a ragged, grey scalp over the soil.
An older fellow jogged past and offered us “A Happy New Year to you!” in passing. We shared the winding road with other joggers and walkers, as well as with cyclists and motorists, and received more somewhat unexpected new year’s greetings, each of which we happily returned in kind. After reading yesterday’s newspaper story, I have to say that I felt a buoyant sense of relief at encountering so many friendly Australians out exerting themselves so early in the morning, because no one who drank $100 worth of booze last night could possibly have faced running, cycling, or even walking up Castle Hill at 8 a.m. this morning.
As we walked, Vilis and I spotted sulphur-crested cockatoos high in the scattered trees screaming out harsh calls and winging heavily from branch to branch, the large, white parrots conspicuous against muted green foliage. A black-faced cuckoo-shrike, which is not related to either cuckoos or shrikes, but rather to orioles, perched slim and elegantly grey near the top of a shrub, its black face and bib like a mask worn by a mysterious entrant to a costume ball. Outside the washrooms near the hill’s 286-metre summit, a friarbird skulked and muttered within a berry-laden tree, stretching out its neck from hunched shoulders to pluck orange berries with its beak.
From a short summit loop track and several look-offs, Vilis and I gazed out over Townsville, capital of North Queensland and, with a population of about 170,000, Australia’s largest tropical city.4 Castle Hill itself resembled a bulky watchtower that overlooked the city centre to the northeast, with its enclave of rising towers, and the dockyards farther to the east. We identified a ferry heading for Magnetic Island, which lies 10 kilometres offshore and is home to populations of koalas within Magnetic Island National Park. Off in the distance to the west, a long, narrow rectangle containing regularly-spaced white tabs revealed itself through my binoculars as a cemetery. Closer to hand, soaring palms and other trees, the first managing to look both graceful and dishevelled at the same time, lined streets and cluttered back yards of houses. The houses clung to the slopes of the hill and sprawled over the river’s floodplain north to the The Strand, west to the vast wetlands we saw from the jet on our arrival, and east and south to the bases of ranges of sharp-peaked hills. Most of the visible homes appeared to be modest, single story structures, but some perched on the rugged slopes of Castle Hill were multi-storied mansions making the most of the million-dollar view.
We began hiking down from the summit on a ‘goat track,’ a rough path past pink cliff faces and massive boulders smeared with crustose lichens in shades of black and pale green. The path soon faded into nothing, so Vilis picked his way downhill over the rough ground. I followed slowly, scanning the terrain for snakes hidden among the jumbled rocks and long, grey grasses.
Australia is the only continent in which venomous snakes outnumber non-venomous snakes.5 Its list of highly poisonous land snakes, sea snakes, and sea kraits, all members of the reptilian family Elapidae, reads like a who’s who of the world’s most venomous.5 In a slim Green Guide publication titled Snakes and Other Reptiles of Australia, author Gerry Swan listed the world’s 22 most venomous snakes, pointing out that the species names printed in italics were not Australian species.6 Of the names listed, only 3 were printed in italics: the Indian cobra, ranked 11th, the king cobra, ranked 16th, and the eastern diamond-back rattlesnake, ranked 22nd.6 All the rest were Australian, with the gold, silver, and bronze medals in the Olympics of snake venomosity going to the inland taipan, eastern brown snake, and taipan, respectively.6 The Townsville area lies within the range of the eastern brown snake and taipan, as well as of at least four other toxic celebrities: the mulga snake, red-bellied black snake, and two species of death adders.7 So, I moved carefully; however, instead of snakes, we found signs of digging and chunky, cylindrical droppings, both of which were likely produced by mammals.
After our return to the car, we drove to the base of the hill and then past Queens Gardens – a tempting enclosure of riotous vegetation – to The Strand. There, white fig trees stood like a line of arboreal fortresses strung with a thousand ropes of aerial roots, and a half-dozen red-tailed black-cockatoos winged low overhead like splinters of night. “Black-cockatoos! Beautiful!” I exclaimed to Vilis.
“They are beautiful, aren’t they?” agreed a trim man pushing two wee, frizzy-haired girls in a stroller. “They’ll be back. They like to eat the Javan almonds.” He indicated a thick-crowned tree beside the path and paused to chat. “When I was a kid, we always used to come down here and pick the almonds.” The picking, he told us, was followed by cutting through the outer husk covering the seed and then smashing open the hard seed shell to get to the seeds. “Inside, there are these long, pencil-like seeds. They taste really good.” He looked out over the park. “That was a long time ago. It’s all different now.” He smiled as he pushed the stroller into motion again. “A Happy New Year to the both of you!”
“Thank you. Happy New Year to all of you,” I responded, and a moment later laughed when one of his daughters repeated her father’s wish in an endearingly indistinct way that turned ‘both’ into ‘boash.’
Even though it was only mid-morning, heat sizzled within the park. The drizzle had long ended. No one walked on the beach, which was posted with warnings about poisonous jellyfish and signs indicating the presence of bottles of vinegar to douse jellyfish stings. A couple of kayakers paddling boats with outriggers beached their kayaks and then took them out onto Cleveland Bay and beached them again. Children and adults dressed in swimming togs splashed in the spray of fountains in a water park and stood expectantly beneath a wide spillway while a huge blue bucket filled with water and then tipped its contents into the spillway and onto them, eliciting delighted screams.
Rainbow lorikeets fed in short palm trees, the birds’ intense array of colours stunning against the blue-green fronds. Silver gulls with scarlet beaks and legs and white eyes carried out a peevish conversation on the beach, while pigeons strutted and diamond doves bobbed on the lawns. With throaty, rasping screeches, the fleet of black-cockatoos returned to the Javan almond tree and its fruit.
For several minutes, Vilis and I watched a solid black male black-cockatoo at work. The large, crested parrot held one of the almond tree’s oval, flattened, green fruits in its left foot while it perched on its right foot. Using its thick, sickle-shaped beak, the parrot ripped off much of the fibrous outer covering of the fruit to expose a hard seed shell, which it then attempted again and again to crack open. Little by little, it succeeded, breaking chips off the shell and tossing them into the air. Inspired by our conversation with the friendly father of the little girls, Vilis collected a couple almond fruits from the grass beneath the tree and tucked them into his pocket. Based on the amount of effort the black-cockatoo was putting into extracting its snack, I figured Vilis had his work cut out for him.
After supper, we learned from a national radio report that Tasmanian devils are plagued by a transmissible form of cancer called devil facial tumour disease or DFTD.8 The disease is spread by biting and causes massive facial tumours that result in death due to starvation because the devils can no longer hunt.8,9 In the past 13 years, devil populations have decreased by up to 70 percent as a result of the cancer spreading among populations and quickly killing individuals.9,10 That this icon of Tasmania, which I first saw portrayed as a slobbering, whirling dervish on Saturday morning Bugs Bunny cartoons, but later became aware of as the largest living marsupial carnivore, should suffer such a grotesque and rapid-spreading disease is disturbing, to say the least. However, in a paper published in the journal Science today, lead author Elizabeth Murchison and her colleagues stated that there may be hope for the stocky Tasmanian carnivores.8,10 Her team identified the cancer as a Schwann cell tumour and has provided a genomic marker that may be useful for developing a vaccine against the disease.8,10 Hearing that story made me want to catch a plane to Tasmania and hunt for devils. Soon.
1. Queensland Government, Queensland Museum. Cane Toad. © The State of Queensland (Queensland Museum) 2010. Accessed 15-Jan-2010. http://www.qm.qld.gov.au/Find+out+about/Animals+of+Queensland/Frogs/Cane+Toad
2. Northern Territory Government, Natural Resources, Environment and the Arts. Exotic Animals – Major Pests: Cane Toad. © Northern Territory Government 2007. Accessed 15-Jan-2010. http://www.nt.gov.au/nreta/wildlife/animals/canetoads/index.html
3. Emily MacDonald. Townsville residents hop into cane toad hunt. Townsville Bulletin, March 30, 2009. The North Queensland Newspapers Company Pty Ltd © January 2007. Accessed 15-Jan-2010. http://www.townsvillebulletin.com.au/article/2009/03/30/47081_hpnews.html
4. Queensland Government, TAFE Queensland. Queensland regions – Townsville. © The State of Queensland (Department of Education and Training) 2010. Accessed 25-Nov-2010. http://www.tafe.qld.gov.au/international/living_qld/regions.html
5. Steve Wilson and Gerry Swan. A Complete Guide to Reptiles of Australia. 2008. New Holland Publishers (Australia) Pty Ltd, Sydney, p. 416.
6. Gerry Swan. Green Guide Snakes & Other Reptiles of Australia. 1998. New Holland Publishers (Australia) Pty Ltd, Sydney, p. 5.
7. Wilson and Swan, pp. 418, 450, 454, 458, 464.
8. Felicity Ogilvie, ABC News. Tumour breakthrough could save Tassie devils. January 1, 2010. © ABC. Accessed 25-Nov-2010. http://www.abc.net.au/news/stories/2010/01/01/2783753.htm
9. Adam Bostanci. A Devil of a Disease. 18 February 2005. Science 307: 1035. Accessed 26-Jan-2010. www.sciencemag.org
10. Townsville Bulletin. Tackling devil of a health challenge. Saturday, January 2, 2010, p. 64.