Biodiversity in the Northern Rivers
The Northern Rivers, New South Wales, is one of Australia's most remarkable natural environments. High rainfall, mild conditions, and dramatic variation in altitude and geology have produced an extraordinary patchwork of ecosystems, including rainforest, wet and dry sclerophyll forest, grasslands, wetlands, mangroves, saltmarsh, heath, and more.
The region was once home to the Big Scrub (at approximately 75,000 hectares, one of the largest areas of lowland subtropical rainforest in eastern Australia), and remains connected to the Gondwana Rainforests of Australia, a UNESCO World Heritage Area. This region supports high numbers of rare or threatened plant and animal species, with approximately 70 plant species and 90 animal species recognised as vulnerable or endangered. Native wildlife found throughout the region includes koalas, wallabies, pademelons, echidnas, platypus, gliders, possums, and lyrebirds, alongside more than 400 bird species and a remarkable diversity of reptiles and frogs.
An Ecological Hotspot
The ecology of the Northern Rivers also punches well above its weight in global terms:
- Frog, snake and marsupial diversity per unit area is the highest in Australia, with species including the green tree frog, Fleay's barred frog, red-bellied black snake, carpet python, spotted-tailed quoll, pademelon and sugar glider
- Bird diversity is second only to the wet tropics, with rainforest species such as the noisy pitta, pale-yellow robin, figbird and logrunner among more than 400 species recorded in the region
- More than half of NSW's plant species occur in this northeast corner
- Species from tropical and temperate zones meet here, many at the very edge of their range
Even the most well-studied landscapes contain surprises. In September 2000, botanists discovered a new species of tree in the Nightcap Range — the Nightcap Oak. It was only the second known species of its genus, Eidothea, a member of the Proteaceae family that includes rainforest trees like waratahs, grevilleas, banksias and macadamias.
The lineage traces back to Gondwana, the supercontinent that began breaking apart more than 120 million years ago, making the Nightcap Oak a rare and ancient survivor.
Where Birdsong Began
Science has confirmed that all the world's songbirds trace their origins to Australia. The earliest songs were sung in ancient rainforests like these, millions of years ago, by the ancestors of today's lyrebirds.
One of the most remarkable of those descendants is Albert's lyrebird, a bird with one of the smallest ranges of any species on the continent. Found only in a narrow band of mountain rainforest along the Border Ranges, Nightcap Range and McPherson Range in far north-east NSW and south-east Queensland, it is one of the region's most special species.
What makes Albert's lyrebird extraordinary is its song. Males are master mimics, capable of accurately reproducing the calls of more than a dozen other species, including satin bowerbirds, king parrots, crimson rosellas and kookaburras, woven together into complex sequences that are socially learned and passed down between generations of birds. During the breeding season from May to August, males perform for hours each day from a mound or cluster of vines in the rainforest understorey.
Chances are you'll hear one before you see it — shy and well-hidden in dense vegetation, an Albert's lyrebird can fill the forest with sound while remaining almost impossible to spot.
