Exploring Daintree

When people think of Australia, the terrain they immediately picture is arid and barren, orange dirt stretching out as far as the eye can see, occasionally broken up by a lone eucalyptus tree bleached completely white by the unrelenting sun. Yes, people think of the outback, which makes sense as over 70 percent of Australia is arid or semi-arid. The interior desert, an area of unforgiving sun, little water, and poor soil, has been imprinted on the collective imagination of those outside Australia as what the land down under really is.

But the coasts of Australia are bursting with life, especially in North Queensland, home to some of the world’s oldest rainforests, which are, in fact, over 120 million years older than the Amazon. The Wet Tropics of Queensland is a UNESCO World Heritage Site encompassing some 894,420 acres of tropical rainforests, home to some of the most bizarre and dangerous creatures in Australia, which is saying a lot thanks to Australia’s penchant for strange and deadly creatures. UNESCO deems it as an area of outstanding universal value in part because of the biodiversity it protects, but also because it offers a unique glimpse into what earth was like millions of years ago as the world we know today was forming. Read on as we venture into the prehistoric Daintree Rainforest National Park.

A Living Relic

180 million years ago, Australia, along with the rest of the Southern Hemisphere, was part of the supercontinent Gondwana. At that time Gondwana was starting to fracture apart into the continents we know today: Australia and Antartica in one big chunk drifting toward the south; India drifting north; South America and Africa drifting together west. Continental drift, as this natural phenomenon is known, happens because of volcanism and plate tectonics, or the movement of huge plates over the earth’s mantle. At deep ocean ridges, fresh magma bubbles up and hardens, pushing that plate further away from the ridge. The continents that rest on these plates are essentially along for the ride, as Australia and Antartica found themselves when Gondwana split.

While all of this was happening in the Jurassic Period, the world was a much warmer place, covered in lush tropical jungles and home to dinosaurs. Even Antarctica was warm and supported a variety of dinosaurs and rainforests of its own. In fact, it shared many species with Australia because the two continents were fused together the longest of any of the former Gondwana continents.

They did not completely split until 45 million years ago. Australia drifted north while Antartica stayed south, eventually freezing as the climate cooled and the Antarctic Circumpolar Current formed around Antarctica, ensuring that cold water always flowed around the frozen continent. All of the rainforests were lost on Antarctica. Australia’s rainforests did not fare much better.

As Australia drifted north, its climate became drier and the rainforests began to retract. Rainforests that had once covered most of the eastern coast of Australia were reduced to the current minuscule cover by the beginning of the ice ages during the Pleistocene Period. As the continent became warmer and drier, the grasslands, eucalyptus forest and arid deserts that comprise most of Australia today began to dominate. Today only 3 percent of Australia’s forests can be classified as rainforests, a tiny amount when considering that much of Australia is not forested. However, continental drift actually helps support Daintree and other rainforests along Australia’s east coast. Australia has been drifting over a volcanic hotspot for the last 30 million years which has led to volcanos dotting much of the coast from Cairns all the way down to Victoria. Daintree and the other rainforests of the Wet Tropics can thank these ancient (mostly dormant) volcanoes for producing the nutrient-rich soil they depend on.

The early rainforests of Australia were spectacular. After the demise of the dinosaurs at the end of the Mesozoic Era, mammals began to fill the empty ecological vacuum left by their former scaly overlords. In the early rainforests of Australia during the Cenozoic Era (65 – 2.6 million years ago), many of the earliest relatives of the marsupials we know today evolved as global mammal diversity exploded. Many of these species probably also inhabited the similar rainforests of Antarctica before it broke away.

The amazing biodiversity of these ancient rainforests is still around in a few pockets. New Guinea has a tremendous overlap of species in its rainforests due to the fall of sea level that has created a land bridge with Australia a few times over the last several million years. In Australia, the wet tropic rainforests of Queensland are the best spot to travel back in time and see what a large swath of Australia and Antarctica used to be like.

In the Daintree Rainforest, the world’s most primitive marsupials still hop, climb or scurry through the leaf litter, living relics from Australia’s tropical past. A perfect example of these living fossils are bandicoots, a rabbit-sized omnivorous marsupial with a pointy nose and large hind feet. They are a part of the more primitive order of marsupials, the Peramelemorphia order (today only consisting of bandicoots and bilbies). These were the dominant marsupials in Australia early on, but have seen their ecological importance retract with the rainforests. The arrival of rats from Southeast Asia was also detrimental to bandicoots. A few species of bandicoot still scurry throughout Daintree, but only 20 exist in Australia overall.

Queensland’s Wet Tropics are one of the last refuges in the world where rainforests have persisted since the time of Gondwana. Along with the ancient marsupials that hide out here in one of their last refuges, ancient plants from the Jurassic Period, like cycads and ferns, mingle with conifers and relatively modern flowering plants in the dense undergrowth competing for the rare ray of light that makes it to the forest floor. It truly is a land before time and offers a glimpse of how the earth used to look.

Daintree Rainforest and Its Amazing Biodiversity

The Daintree Rainforest, Australia’s largest remaining rainforest, is estimated to be around 180 million years old. However, it was only discovered by European explorers very recently. George Dalrymple first explored the region in 1873, naming the river he traveled down after the government geologist, and his boss, Richard Daintree. Of course, the area has been inhabited for thousands of years by the Kuku Yalanji people, but the Daintree name stuck and today the river and the surrounding rainforest still bear his name.

In addition to being the world’s oldest rainforest, Daintree is also one of the most important to science because of its high levels of biodiversity and opportunity for scientific breakthroughs as a time capsule of Gondwana rainforests. While roads were being built throughout the park in the 1970s, one of the most important scientific discoveries in Australian history happened when the so-called idiot fruit, Idiospermum australiense, was discovered in the rainforest. It is one of the world’s most primitive flowering plant and incredibly rare. It only occurs in the World Heritage-listed rainforests surrounding Daintree and is called the idiot fruit because of its idiosyncratic nature. It also has the largest single seed of any tree in Australia, which is similar in size to a human’s balled-up fist. Its re-discovery in 1970, when the last specimen had been found in 1902, highlighted North Queensland’s tropical rainforest as a treasure trove for scientific discovery.

In addition to its importance to science, UNESCO also lists these rainforests because of the amazing biodiversity they protect. These rainforests are home to 3,000 species of vascular plants, with 576 species being found nowhere else on earth. The Daintree Rainforest, in particular, is home to 30% of Australia’s frog species, 20% of Australia’s reptile, and 30% of the continent’s marsupial species. 65% of the country’s bat and butterfly species fly through the forest. Out of the 368 species of birds found in the region, 11 are found nowhere else. This is spectacular because the Wet Tropics of North Queensland covers only 0.2% of Australia. These forests are a bastion for endemic species conservation.

The diversity of species here is outstanding, but the species are also incredibly interesting. If you are traveling along and see a glint of iridescent blue flash in front of you, it is from the sun reflecting on the wings of the Ulysses butterfly. It is one of the most beautiful creatures to watch as it erratically flies through the dense undergrowth of the forest.

Although one is unlikely to cross paths with a tree kangaroo, the Wet Tropics are home to two species of them, the Lumholtz’s and the Bennett’s tree kangaroos. Unlike their iconic relatives that bound across the outback, these kangaroos prefer to spend most of their time in trees, bouncing from tree top to tree top, in pursuit of fruit to eat. The 13 species of tree kangaroos decided to diverge from their macropod relatives (kangaroos and wallabies) and return to the trees where they first evolved from many millions of years ago in forests like Daintree. They are an interesting example of continuing evolution as they re-adapt to life in the trees: their legs are becoming shorter and their forearms are becoming stronger for all the climbing they have to do. These two species of tree kangaroos are the largest tree-dwelling mammals in Australia.

Several interesting species of reptiles live in the Daintree Rainforests. Australia’s largest snake, the Amethystine Python (aka the scrub python), uses heat-sensing pits in its head to hunt down its prey throughout the rainforests. It can grow up to 25 feet long and in the right light, its scales will give off a similar hue to the purple amethyst gem. The curious snake occasionally ventures out of the rainforest and into suburban homes. Racing through the forest floor is the Boyd’s forest dragon, a medium-sized lizard that usually has a large yellow blotch behind its eye as a striking contrast against their brownish-green body. Unlike most other lizards, they do not bask. Their body temperature instead fluctuates with the air temperature. This means the lizards are only active during the day and are quite cryptic due to their camouflage.

In addition to bandicoots, several other primitive marsupials exist in the rainforest trying to avoid scrub pythons. In the trees, the common striped possum uses its extended fourth finger to dig grubs out of bark. On the ground, swamp wallabies hop around, content with their decision to stay terrestrial as the tree kangaroos crash through leaves high in the trees. The most primitive and smallest species of the macropod family also exists in these ancient rainforests. The musky rat kangaroo searches the rainforest floor for fruit and insects and hops around like its much larger descendants. As the name suggests, it is a similar size to a rat. The spectacled flying-fox is one of the Wet Tropics most recognizable non-marsupial mammals. They have a light patch of fur around their eyes that gives them their namesake “spectacles” (read more about the dangerous climate facing Australia’s flying foxes here).

The two most interesting species in the Daintree Rainforest and Wet Tropics as a whole were the two most iconic and dangerous species in the jungle. Lurking throughout the Daintree River and other waterways are saltwater crocodiles (Crocodylus porosus), the largest and most widespread species of crocodile in the world. In Northern Queensland, swimming in any open waterway carries a deadly risk as the saltwater crocodile can tolerate both fresh and saltwater and has one of the strongest bites on the planet. They can grow up to 20 feet and eat anything foolish enough to get near the water’s edge.

Crocodiles have been existing in rainforests like these for tens of millions of years. But the amount of crocodiles in the Daintree River got dangerously low in the early 1970s as the tremendous animals were hunted for their hides. In 1974, legislation was passed to protect them and today the population has rebounded to a respectable 70 estimated adults in the Daintree River. Spotting crocodiles on boat cruises throughout the river is a big tourist draw. When I went, I was lucky enough to spot three crocodiles, including one juvenile, one adult female and one huge adult male close to 20 feet named Scarface because of a large scar over his mouth. I would not want to see what the crocodile that did that to him looks like now.

Above: a juvenile, an adult female and an adult male (“scarface”) saltwater crocodile

The other iconic creature in this area is one of the most spectacular birds in the world (it does adorn this site’s homepage). It looks like Big Bird with a bright blue head, black feathers and legs that belong to a large predatory dinosaur. The Southern cassowary (Casuarius casuarius) is one of the world’s largest birds, weighing easily over a hundred pounds and standing 6 feet tall. Although it eats fruit (including those with seeds laced with cyanide that the bird can pass through its system without being poisoned), it has a nasty reputation as the world’s most dangerous bird, thanks to its aggressive and territorial nature and a deadly inner nail (on their middle toe) which can slice someone open just like a dagger. A few days before we visited Daintree, a Florida man had been killed by a cassowary after he was kicked by the large bird. This was the first confirmed cassowary kill since 1926, although attacks seem to happen at least once every year. This tragedy seemed to have the macabre effect of making us want to see a cassowary even more than we already did. Unfortunately (or fortunately depending on your point of view), the deadly birds are very reclusive in the wild.

Cassowaries, which also live in rainforests in New Guinea, are very ecologically important to the wet tropics. Because they eat fruit, they pass the seeds throughout the forest after it passes through their system. Unfortunately, cassowaries are endangered throughout their range. The World Heritage site offers some safe haven but the magnificent birds are still struck by vehicles as they try to cross the road. In 2014, there were estimated to be only 4,000 cassowaries in the entire Wet Tropics region and their population is decreasing according to the IUCN.

Threats to Daintree and the Wet Tropics

UNESCO estimates that roughly 80% of the Wet Tropics rainforest is still intact since the arrival of Europeans, which is extremely great compared to other swaths of tropical forests around the world. Its distinction as a World Heritage site, as well as efforts by the Australian and Queensland governments to ban logging in 1987, have helped the forest remain pristine over the past few decades. However, much of the lowland forests around the protected rainforests have been cleared, leading to rainforest fragmentation. Human disturbances, such as roads and abandoned mine shafts, throughout the rainforest still affect the natural environments.

Another threat toward the unique wildlife of the Wet Tropics is the continued existence of invasive species, like feral pigs and cats, that threaten ecological roles by outcompeting or hunting native animals. Most of these animals are not equipped to face these strange animals from other parts of the world.

Of course, as with every other inch of our remarkable planet, climate change will threaten the existence of this tremendous pocket of Gondwanian rainforest. As the temperatures continue to warm, UNESCO predicts that the rainforest size will shrink and the range of suitable habitats for every animal in the rainforest will likewise retract. Although climate change may seem overwhelming at times, a huge part of the solution is forests like the Wet Tropics because trees can act as a carbon sink. They are able to absorb the harmful atmospheric CO2 from the air and recycle it into safer, less harmful gases. Planting more trees, as well as protecting the forests we have left, will be key to curbing the effects of climate change. Several deforested areas around the Daintree National Park have been replanted with trees to protect the forest’s integrity, take carbon out of the atmosphere and offer habitats to threatened species of animals. The survival of unique and incredible rainforests like Daintree and the Wet Tropics are not only vital for the animals that live there, but also for our survival on this planet.

Three Things You Must Do When At Daintree Rainforest

1. Definitely head to the amazing views at Cape Tribulation. The area was named by legendary explorer James Cook after his ship ran aground on the Great Barrier Reef, which is right off the coast from Daintree, in 1770. Today it offers the spectacular combination of intact rainforest and pristine beach, although be wary of swimming. Saltwater crocodiles and box jellyfish make this one of the most dangerous beaches in the world.

2. Stop at the Daintree Ice Cream Company. Well worth it for anyone who likes ice cream (who doesn’t like ice cream?), the Daintree Ice Cream Co. offers four unique flavors every day from their tropical fruit orchards. When I was there, the flavors were wattle seed (creamy, coffee-like flavor), Davidson plum (the best one in my opinion, very fruity), mango and banana. When is the next time you’ll have wattle seed ice cream?

3. Take a dip in one of the swimming holes throughout the park. There is definitely nothing like hopping in a natural creek in the middle of a rainforest, especially on a nice warm day. The cool, clear water is full of tiny fish that will swim up and examine you. Before jumping in, it would be a good call to check to make sure there are no crocodiles in that particular swimming hole. That would be a tough way to end your trip to Daintree!

All photographs and art done by Jack Tamisiea.

Sources:

https://whc.unesco.org/en/list/486/

https://www.livescience.com/37285-gondwana.html

https://www.worldwildlife.org/species/tree-kangaroo

http://www.destinationdaintree.com/the-daintree/wildlife/mammals

https://daintreerainforesttour.com.au/blog/the-salt-water-crocodiles-of-the-daintree-rainforest/

https://www.washingtonpost.com/science/2019/04/14/florida-cassowary-attack-man-dies-after-encounter-with-worlds-deadliest-bird/?noredirect=on&utm_term=.63c5e78cb73d

https://www.iucnredlist.org/species/22678108/131902050