An exceptional biological diversity
In 1971, long-time local residents John and Linda Nicholas returned home from a weekend in Mossman to find four of their cattle dead. Suspecting foul play, the Department of Primary Industries divisional veterinarian was called in, only to find another two beasts in the throes of death.
Large, partially masticated seeds in the digestive systems of the cattle were found to be the cause of death through poisoning, which was not dissimilar to symptoms displayed from the ingestion of strychnine.
Herbarium records revealed a previous reference to the species ”Calycanthus australiensis” (Diels 1902), however taxonomic anomalies favoured the discovery of a new species, which became ”Idiospermum australiensis”.
At the time, there were only eighteen known ancient flowering plant families on earth. Idiospermaceae became the nineteenth. Its re-discovery stimulated intense botanical interest in the rainforests of the Daintree. The scientific community had discovered a living museum of plants and animals of indeterminate antiquity.
Almost immediately, impassioned scientific concern reverberated through the hallways of public office, initiating a conservation effort that would ultimately occupy Australia’s collective environmental conscience.
It is interesting to note that throughout its sixty-nine year displacement from scientific awareness, the rainforest dinosaur ”Idiospermum australiensis” was being selectively logged under its common name ‘Ribbonwood’. Members of the local community attending to the business of life were intimately aware of the special qualities of the plant, along with some seven hundred other rainforest cabinetwood timbers and the complex rainforest habitats in which they grew.
Just as the Colonial Office had claimed ”terra nullius” over the island continent that became Australia; transporting English values, flora and fauna to the antipodes without considering the rights and entitlements, let alone the cultural and intellectual wisdom of the indigenous inhabitants, so too were landholders within the Daintree unscrupulously displaced to make room for more aggressive and more abundantly resourced external interests.
Once again, the rights of legitimate occupants were trampled to allow the hostile take-over of the landscape. Social justice and equity were unconscionably displaced in the fervour for wealth through tourism and political popularity through a succession of ‘save the Daintree’ campaigns.
The aspirations of the host community, to protect and conserve their rainforest lands through an economy based on sustainable eco-tourism has been undermined by external interests while the continued revegetation and rehabilitation of the area by the local landowners has never been acknowledged.
Cooper Creek Wilderness recognises the present as a mere blink of an eye in the full life of the ancient rainforests of the Daintree. Notwithstanding, its fate lies precariously in the hands of humankind, today.
The rainforests of the Daintree aren’t so conveniently constructed to allow science, or indeed any sector, corporation or individual, omniscience. Whilst being part of rigorous and methodical disciplines, scientists are merely a collection of people with the very same physiological capabilities as those from other walks of life. The rainforests of the Daintree, however, reveal their secrets slowly, sometimes incredibly so.
Cooper Creek Wilderness is a strategically important part of the rainforests of the Daintree. Its directors live and breathe the very same air as the plants and animals that scientists collect, measure and catalogue. On a daily and nightly basis they present World Heritage values to visitors from around the world. Even with passionate and diligent application to the task, it is undisputed that comprehensive knowledge will be revealed at the behest of the rainforests of the Daintree.
It is also important to note that one hundred and thirty-five million years of evolution in an environment of intricate complexity and intimidating density, has allowed the development of spectacular strategies for inconspicuousness and evasion. Not the least of which includes nocturnal activity under the inky veil of almost absolute blackness in the rainforests of the Daintree.
Visitors from around the world, who have managed to bypass regional tourism advice and stay overnight in the Daintree for a number of consecutive days, have demonstrated considerable enthusiasm for nocturnal forays into the rainforest. Equipped with torchlight and an expert local guide, these adventurous souls seek face-to-face encounters with a myriad of nocturnal possibilities.
Cooper Creek Wilderness provides guided and interpreted access to such opportunities. Upon entry to the rainforest, all lights are extinguished. The blackness is overwhelming and almost invariably one or two lights will instinctively be turned back on. With encouragement, the blackness is allowed to envelop the group.
Participants are asked to imagine the perspective of the rainforest inhabitants. In order to function successfully and at all heights within such an incredibly dark habitat requires such a keen sensitivity to light that the conspicuousness of the group’s single-file procession with flashlights blazing is almost ludicrous.
Wildlife is aware of the group’s approach. As proximity decreases so too does the likelihood of the animal’s departure increase. It is the sounds and movement of associated vegetation with the departure that provides members of the group with their greatest advantage for a successful sighting.
Because of the rarity and endemicity of fauna inhabiting the finite rainforests of the Daintree, a considerable amount of research has been undertaken to ensure that the popularity of ‘night-spotting’ tours does not come at the expense of Australia’s international obligations defined within the World Heritage Convention.
The level of distress experienced by wildlife correlates with the factors of light-intensity and duration. It is a cumulative impact. Cooper Creek Wilderness’ clientele are advised of the relationship, provided with appropriately powered torches and encouraged to regulate the intensity and duration of their beams off the eyes of nocturnal fauna. Heavy emphasis also orients participants to the responsibilities that come with entry into environmental circumstances that have essentially precluded a nocturnal human presence prior to market-demand and the availability of reliable torchlight.
One of the prevailing trends within the nocturnal landscape is the strategy employed by sleeping birds and lizards to remain safe from arboreal snakes. A sleeping position is selected at the last possible moment before nightfall on vegetation that cannot be accessed without traversing the often-flimsy branch upon which the animal sleeps. Its instinctive sensitivity to vibration provides protection. In many circumstances birds and lizards are found sleeping in positions that would make them vulnerable to human collection. The inference excludes a historical human foraging presence and the challenge on nightwalks is to bypass these animals without introducing vibration.
It is an exercise in cooperation conducted in as much silence as possible. Environmental factors including temperature, rainfall and moonlight have a profound effect on the likelihood of a successful night. The most ideal circumstances occur on the hottest, wettest and darkest nights. By contrast, the coldest nights in the middle of a dry period with a full moon are unlikely to reveal any fauna whatsoever. Even so, the sounds and sensations of the rainforest at night provide a unique experience.
It is a major frustration that tourism-marketing trends encourage peak visitation in the dry season, when the rainforests of the Daintree are at their most secretive. For those visitors who attend in more ideal circumstances, the rewards are bountiful.
Moonlight provides advantages for the nocturnal birds of prey. The unmistakable ‘falling bomb’ call of the Lesser Sooty Owl Tyto multipunctata penetrates the density of its rainforest habitat with its shrill, descending whistle. Small mammals, birds and insects are vulnerable to this proficient hunter.
The Rufous Owl ”Ninox rufa” is a most formidable predator. A large male may weigh up to 1.3 kilograms and is capable of taking adult Orange-footed Scrubfowl from their perches in flight. Spectacled Flying Fox, White-tailed Rats and Water Rats are known prey to this powerful rainforest inhabitant.
The Papuan Frogmouth ”Podargus papuensis” may be bigger than the Rufous Owl but less than half its weight. It is seen on nightwalks when its superbly camouflaged plumage is betrayed by huge red eye-shine reflections in the beam on the nightwalker’s torch.
But it is in circumstances of almost absolute darkness, unsuitable for predatory opportunities of the owls, which brings the most abundant nocturnal activity.
As a general rule in nature, wherever there are insects, spiders will be found. The rainforests of the Daintree are home to millions of insects. There is a corresponding abundance of spiders. The most common are the Wolf spiders, large, open-range hunters that are conspicuous at all heights within the forest by their distinctive eye-shine reflection. At the primitive end of the collection, are the large Brush-footed Trapdoor Spiders, also known as Whistling or Barking Spiders because of their ability to produce sounds through stridulation or the rubbing of the palps against the chelicerae. Net-casting spiders are found with their uniquely blue-tinted net-web held motionless above an obvious insect thoroughfare and with blistering speed and agility expand the highly elastic rectangular construction over passing prey. Perhaps the most spectacular of the Daintree spiders is the Golden Orb-weaving Spider ”Nephila maculata”. The largest of world’s master weavers, its unmistakably golden web can exceed one metre in diameter and is strong enough to break the momentum of tiny birds and insectivorous bats.
The insect life defies imagination. The total number of different species would be in the thousands. Some of the more distinctive examples include the enormous Hercules Moth ”Coscinocera hercules”, which can attain a wingspan of 27 centimetres. The female, without a mouth, only lives for about two days or as long as her fat deposits last. Another spectacular moth species is the ”Lyssa macleayi” (formerly ”Nyctalemon patroclus”) which may reach a wingspan of 13 centimetres.
One of the world’s largest dragonflies, the Giant Petalurid Dragonfly ”Petalura ingentissima”, has a wingspan of up to 16 centimetres. It is frequently sighted within the Cooper Creek channel as its nymphs live in burrows within the creek bank.
20 centimetre-long antennae are not unusual on one of the larger and more ornate orthopteroids of the Daintree. The Spiny-legged Rainforest Katydid ”Phricta spinosa”, is also known as the ‘Wait-a-while Cricket’ because of its cryptic similarity to the notorious palm in which it hides. Females are easily distinguished by the presence of a curved, elongate ovipositor extending from the abdomen. Growth is achieved through the moulting of the exoskeleton, with a successive enlargement until adulthood in as many as ten moults or instars. Sharp, spiny, powerful hind legs may be kicked out in defence.
Though not necessarily rare, the speed and evasiveness of the Scutigera sp. make them seldom seen creatures. Scutigera are very ancient animals with fossil records dating back to the Carboniferous Period. Possessing characteristics intermediate between the arachnids and the centipedes, they are in fact in a group by themselves and are venomous carnivores.
A Gondwanan creature of ancient lineage, the Peripatus has been dated back to the Cambrian period, 500 million years ago. Sometimes referred to as ‘Velvet Worms’ or more technically ‘Onychophorans’, the peripatus is a voracious, nocturnal predator. Two antennae protrude from the head and a white, sticky fluid is squirted either in defence or to ensnare their prey. Once immobilised the by the sticky threads, small arthropods and invertebrates are readily consumed.
Reptiles dominate the rainforests of the Daintree probably more so than other tropical rainforests of the world. Cooper Creek Wilderness has a diverse representation from the most dangerous terrestrial predator in Australia, the Saltwater Crocodile ”Crocodylus porosus” to the most innocuous insectivorous rainforest skink.
Distinctive lizards inhabiting Cooper Creek Wilderness include the Boyd’s Forest Dragon ”Genocephalus boydii”, Eastern Water Dragon ”Physignathus lesueurii”, Chameleon Gecko ”Carphodactylus laevis” and the Northern Leaf-tailed Gecko ”Phyllurus cornutus”.
Australia’s longest snake, the Amethyst Python ”Melia amethistina” has reached 8.5 metres and dominates the nocturnal landscape of the Daintree. It moves through the upper canopy as easily as it does along the forest floor and finds prey with the evolutionary advantages of facial heat sensing pits that house infrared receptors.
Another frequently seen nocturnal tree-climbing snake is the colubrine Eastern Brown Tree Snake ”Boiga irregularis” (opposite). Also known as the Night Tiger Snake, this masterful and venomous climber is unusual in Australia, being equipped with rear fangs.
A surprising number of visitors comment on the unexpectedly tolerable levels of mosquitoes. Credit belongs to the effectiveness of insectivorous sonar producing micro-bats at night and to a lesser extent, the White-rumped Swiflets ”Aerodromus spodiopygius”, during the day.
To the bemusement of many visitors, no effort is required to find leeches, which become active with the smallest amount of rainfall. They stand erect and wave their bodies around to detect changes in light intensity, temperature, vibration and smell with sensory organs and chemical receptors on their head. They may have one or more pairs of eyes.
Leech bites are believed to not transmit disease. Using semi-circular and many toothed jaws and under the effect of a desensitising numbing agent, they make an incision in the skin into which anticoagulant and histamine are secreted, along with a mucous that helps the sucker to adhere.
For many visitors to the rainforests of the Daintree, a nocturnal walk is sought in the hope of finding one of the mammals of the night.
Although seldom seen, Platypus ”Ornithorynchus anatinus” and Echidna ”Tachyglossus aculeatus” are inhabitants of Cooper Creek Wilderness. So is Australia’s largest carnivorous marsupial, the Spotted-tailed Quoll ”Dasyurus maculatus”.
Bennett’s Tree Kangaroo ”Dendrolagus bennettianus” inhabits rainforest at both high and low altitudes north of the Daintree River, in an area of only about 50 by 70 kilometres.
The Northern Brown Bandicoot ”Isoodon macrourus” and the Long-nosed Bandicoot ”Parameles nasuta” are seen much more frequently.
Red-legged Pademelon ”Thylogale stigmatica” is an inhabitant, as mentioned previously, which has suffered substantial population decline through the impacts of 1999’s Tropical Cyclone Rona.
The adorable Striped Possum ”Dactylopsila trivirgata” is extremely agile and negotiates the heights of the upper canopy with great competence. They perform spectacular leaps from the branches of rainforest giants to the safety of the numerous fan palms in the secondary story, announcing their presence with an unmistakable crashing sound.
They have acute hearing and detect beetle larvae in rainforest timbers by tapping likely haunts with the ‘palms’ of their front feet. At the faintest sound of agitation, the possum will ferociously tear into the timber with its sharp and powerful incisors. It has an elongated fourth ‘finger’ on each of its front feet for the purpose of extracting its preferred food supply.
It is the nature of wilderness that allows wildlife the freedom to elude the very best efforts of even the most conscientious nightwalkers. Success reflects the richness of biodiversity and the general abundance of wildlife in arguably Australia’s most ‘alive’ terrestrial landscape. This is particularly pertinent within the rigorous regulations that preclude random searching.
Cooper Creek Wilderness has an established pattern of eight kilometres of walking track. Nocturnal searches are rotated throughout the various alternative circuits to minimise the likelihood of anticipation.
Living within Cooper Creek Wilderness has enabled its directors to become more familiar with the habitats, food sources of wildlife and interrelationships that are often revealed through subtle repetition across the annual cycle of seasons.
The flowers of the Javan ash ”Ryparosa javanica” emit a slightly off-smell like rotting meat or five-day-old socks. Attracted insects pollinate the flowers and in turn becomes a smorgasbord for tree frogs. Amethyst Pythons and Brown Tree Snakes are aware of the relationship.
The bumpy satin ash in flower is a great favourite with the striped possum.
Knowledge of the forest and its inhabitants improves with continuous contact and research. Cooper Creek Wilderness has been fortunate in the obliging assistance and information provided by experts in several disciplines, but because of the diversity and complexity of this environment, there remain infinite challenges ahead.
Even more challenging is the battle for acceptance as “legitimate” World Heritage land managers with a shared responsibility and a right to conserve, protect, rehabilitate, present and transmit its values to future generations.