Nature, culture and history
More than 180 species of birds have been recorded in and around Lake Eacham. Most visitors will see the mound-building Australian brush-turkey Alectura lathamii along the roads in the park and in the day-use area. Grey-headed robins Heteromyias cinereifrons hop along forest tracks or perch sideways on tree trunks. In summer, male Victoria's riflebirds Ptiloris victoriae can sometimes be seen displaying on exposed perches. Listen for the distinctive whip-crack call of eastern whipbirds Psophodes olivaceus and the harsh, mewing call of spotted catbirds Ailuroedus melanotis. When the fig trees in the day-use area are fruiting, look for the tiny double-eyed fig-parrot Cyclopsitta diophthalma macleayana. In the Wet Tropics both sexes have a red forehead and males have a red cheek patch.
Amethystine pythons Morelia kinghorni, reputedly Australia's largest snake, inhabit the Lake Eacham forest. Averaging 3m in length, but occasionally reaching around five, these magnificent reptiles are patterned brown and yellow with an iridescent sheen. Non-venomous, they hunt mammals and birds at night using heat-detecting organs in their jaws. When driving through the park at night during the warmer parts of the year, these pythons can occasionally be seen crossing the road.
Boyd's forest dragons Hypsilurus boydii have a habit of perching on small tree trunks, about one or two metres from the ground, to watch for passing insect prey. Although up to 45cm long and quite colourful, these lizards are surprisingly well camouflaged.
Saw-shelled turtles Wollumbinia latisternum are commonly seen in Lake Eacham. They are mainly carnivores, feeding on a variety of foods from crustaceans and molluscs to tadpoles and frogs. They can appear very tame, paddling over to visitors when they appear. Please do not feed the fish and turtles.
Bandicoots, antechinuses, possums, kangaroos, rats and bats have been recorded at Lake Eacham. On the forest floor, it is not unusual to see the smallest member of the macropod family, the musky rat-kangaroo Hypsiprymnodon moschatus. Not much bigger than a large guinea pig, it forages for fruit by day. Visitors may also see another small wallaby, the red-legged pademelon Thylogale stigmatica, browsing on the forest floor during the day.
Twenty-five species of bats have been recorded in and over the Lake Eacham forest. The larger spectacled flying-foxes Pteropus conspicillatus are social animals that usually live in large colonies or camps and can be seen flying over the lake near dusk and dawn. Microbats are smaller, with wingspans of around 25cm. They use echolocation, much more than eyesight, to navigate and find their insect prey.
The cool, wet rainforest of Lake Eacham is well suited to frogs. Three species of treefrog, the dainty green treefrog Litoria gracilenta, eastern dwarf treefrog Litoria fallax and orange thighed treefrog Litoria xanthomera, are found at Lake Eacham. Camouflaged in the leaf litter are mottled barred frogs Mixophyes coggeri and northern barred frogs Mixophyes schevilli. Flattening their bodies and lying very still, they’re nearly impossible to see. The male robust whistlefrog Austrochaperina robusta also calls at night from the forest floor, making a series of short, high pitched chirps arranged in couplets. Male ornate nurseryfrogs Cophixalus ornatus ‘beep’ from perches up to 2m from the ground.
Until the mid 1980s three types of native fish—the Lake Eacham rainbowfish Melanotaenia eachamensis, purple-spotted gudgeon Mogurnda sp. and flyspecked hardyhead Craterocephalus stercusmuscarum—had lived undisturbed in Lake Eacham for thousands of years. These fish grew to about 10cm long and shared the water with freshwater crayfish, platypus Ornithorhynchus anatinus and saw-shelled turtles Wollumbinia latisternum.
In 1984 numbers of these fish began to decline and by 1987 the flyspecked hardyhead was the only native fish remaining. Gone too were the freshwater crayfish. At the same time, other species of fish began to appear, thoughtlessly introduced into the lake. Although these intruders—archerfish Toxotes chatareus, barred grunter Amniataba percoides, mouth almighty Glossamia aprion, eastern rainbowfish Melanotaenia splendida splendida, bony bream Nematalosa erebi and others—are native to Australia, they are not native to this lake and have out-competed Lake Eacham's ‘true locals’.
In 1989 an unsuccessful trial reintroduced 3000 Lake Eacham rainbowfish into Lake Eacham. None were found in surveys conducted six months later. Today, at least nine types of fish are found in Lake Eacham.
Although the lake’s true residents are available in captivity and breed readily, they could only survive in the lake if all of the introduced fish were first permanently removed—something impossible to achieve.
A lesson can be learned from the mistakes made at Lake Eacham. Animals belong in their own habitats where they make important contributions to the local ecosystem. When different animals are introduced, plants and animals in the area are affected.
Geology and landform
The volcanic features of the landscape on this part of the Atherton Tableland are between 10,000 (Pleistocene) and two million (Pliocene) years old. Lake Eacham is a maar—a volcanic crater formed by two massive explosions from superheating of groundwater. This vent now forms the catchment of the lake and is 65m deep. Some of the original underlying sedimentary rocks occur today as metamorphics outcropping in parts of the crater rim. No streams flow into or out of the lake, with water only lost through seepage and evaporation. The water level can fluctuate 4 m between wet and dry seasons.
Differences in soil type, drainage and past disturbances have a profound effect on vegetation type around Lake Eacham. Beside the road to the east lies a structurally ‘simple’ rainforest type that occurs commonly on less fertile soils, derived from metamorphics. These grey soils are distinct from red basaltic soils. Notably absent in this forest type are trees with large buttresses and great complexity of life forms. Here the trunks are more uniform in size, producing a ‘pole forest’ appearance, and are typically covered with white and grey lichens. This contrasts with the forest growing on the more fertile basaltic soils which occur around most of the crater. This complex forest has tree trunks of variable size, an uneven canopy, and epiphytic plants and vines at various heights. Fishbone ferns, characteristic of forest on metamorphic soils, are replaced by maidenhair ferns.
Early in the century, a large part of the forest to the east of the lake was cleared and used for a variety of farming. At the start of the track, travelling clockwise from the picnic area, a 5 acre section was again cleared during World War II. These previously cleared areas show a marked change in vegetation type, evidenced by a predominance of wattles in the canopy and a large number of young rainforest species in the understorey.
There are 10 known species of near threatened (rare) and threatened plants around Lake Eacham.
The area was first surveyed in 1886 and subsequently subdivided into farm blocks for settlement. In 1888 the natural and recreational significance of the lake was recognised and the area of the lake and a narrow band of shoreline vegetation was proclaimed a scenic reserve. At different times during its history, Lake Eacham had a guesthouse, and power boating and water skiing were allowed on the lake. It wasn't until 1934 that Lake Eacham was gazetted a national park.
In October 1943 the Commonwealth of Australia cleared 5 acres of the picnic area and developed an amenities centre for Australian Military Forces (AMF) personnel. While in this area, the AMF installed a new diving platform and jetty, and built toilets, changing sheds, picnic facilities, paths and steps. The dressing sheds and turtle viewing deck were also repaired. Concrete steps, toilets, changing sheds and a jetty were also built. The AMF used the area for 2 years.
In 1988 Lake Eacham was included within the Wet Tropics World Heritage Area (WTWHA) and in 1994 joined Lake Barrine under a single protected area—Crater Lakes National Park.
Crater Lakes National Park is within the WTWHA. Proclaimed in 1988, the WTWHA extends for about 450km between Cooktown and Townsville. Consisting of nearly 900,000ha, vegetation includes tropical rainforest open eucalypt forest, wetlands and mangrove forests. The WTWHA meets all four natural criteria for World Heritage listing. These criteria recognise the area's exceptional natural beauty and the importance of its biological diversity and evolutionary history, including habitats for numerous threatened species. The WTWHA also has cultural significance for Aboriginal people who have traditional links with the area and its surrounds.
Find out more about the Wet Tropics Management Authority.
Aboriginal stories of the explosion of Lake Eacham describe the forest at the time as ‘open scrub’. A subsequent study of pollen records from lake sediments confirms this view, suggesting the rainforest formed on the tablelands only around 7600 years ago.
- Temporary closure: TREAT Rainforest Display Centre, Lake Eacham section, Crater Lakes National Park 4 May to 1 June 2022
- Upcoming works notification: Lake Eacham circuit track, Crater Lakes National Park 1 July to 31 August 2022