The Ulysses butterfly brings us to a halt. We are on the Atherton Tablelands, south-west of Cairns, to look for the rare and elusive Lumholtz’s tree-kangaroo, but the incandescent blue, sparking with each wing beat, is impossible to ignore.

The butterfly dances along the rainforest edge, azure iridescence alternating with the dead-leaf dullness of the underwing. Then it flies up high, as if pulled on a string. One more flash and it is gone. We get back to our search.

The Wet Tropics region of Far North Queensland is home to two species of tree-kangaroo. All kangaroos and wallabies are descended from a climbing possum-like ancestor, but these far northern wonders of evolution have abandoned that ground-level hopping life and returned back to the canopy.

Bennett’s tree-kangaroo lives in the lowland rainforests of the Daintree area, between Port Douglas and Cooktown. Finding it requires a long slog through dense scrub. Lumholtz’s tree-kangaroo lives on the Atherton Tablelands, where sightings are close to coffee and scones.

We start at Curtain Fig national park, near the town of Yungaburra. The centrepiece of this pint-sized national park is a giant strangler fig thought to be about 500 years old. The dramatic curtains of roots are 15 metres tall and prop up a massive trunk, topped with branches draped in ferns and orchids.

A flat boardwalk loops around the fig, protecting the forest from visitors, and the visitors from stinging trees, which grow wherever sunlight breaks through.

The rainforest here is mabi forest, named after the Ngadjon word for tree-kangaroo. Once widespread on the Atherton Tablelands, much of the mabi forest was cleared by settlers. They took tall trees for timber and turned over the land to dairy herds. This endangered ecosystem is now restricted to patches and splinters in national parks and on private land.

The tourist potential of the rainforest has long been recognised. In the 1920s, trains brought people on excursions from the sultry coast, and taxis and coaches carried sightseers up the winding roads from Cairns to the “jungles” of the Tablelands.

A century later, the train line is now a walking track, and the vehicles have air-conditioning and comfortable suspension, but the patches of rainforest remain the same.

Curtain Fig National Park is bustling with birds. Pied monarchs with impeccable black and white plumage and powder-blue rings around their eyes search tree trunks for insects. A brush-turkey rakes through leaf litter. Somewhere in the forest, a wompoo fruit-dove recites its name.

We look up into the canopy. There are small movements – birds and butterflies – but nothing that looks like a tree-kangaroo.

No commotion of shaking leaves. No long tail dangling like a rainforest vine. No rounded shape that appears both out of place and completely at home.

This park is a good location for these unusual marsupials, but this morning they must be elsewhere. We head back to town for breakfast. There are other spots to try.

Our next destination is a 15-minute drive from Yungaburra. We take the back roads past cattle paddocks and avocado orchards to the busy dairy town of Malanda with its vast two-storey wooden hotel and picture theatre that has been showing movies since 1929.

At the edge of town, the North Johnstone River cuts through the rainforest and cascades down basalt steps into a swimming pool. Malanda Falls conservation park is another block of rainforest saved from clearing. Like Curtain Fig, it is a reliable place for tree-kangaroos. The visitors’ centre keeps a record of sightings.

We follow the dirt track through the rainforest, checking for tell-tale claw marks on tree bark, looking up for tails and furry forms. The river is now far below, tumbling over rocks. Two whipbirds duet, the male’s whipcrack followed by the female’s tuneful whistle. A red-legged pademelon, a miniature rainforest kangaroo, bounds away. Its hind feet stamp out a warning.

When Norwegian explorer Carl Lumholtz encountered a tree-kangaroo on his 1882 expedition to Queensland, he described it as “the most beautiful mammal” he had seen in Australia – so much better proportioned than the ungainly ground-dwelling kangaroos and wallabies.

I’d argue the tiny pademelon whose solid backside and long, white-tipped tail just disappeared among the trees still manages to do all right for itself, despite its apparently dodgy dimensions. I do worry that it might be the only marsupial we see today, but that’s the way it is with nature. You see what you see.

There are two more possibilities on my list: Nerada Tea Plantation at Glen Allyn, and Peterson Creek, back at Yungaburra, both are easily accessible by car, with well-made walking tracks.

But as we stand in the carpark considering our next move, I glance across to the wall of trees. And there, just above the start of the rainforest track, is a commotion of shaking leaves.

We get closer and see a long tail that is, indeed, dangling like a rainforest vine. Then a fuzzy face peers down, curious at the gawkers below. The dark eyes are contemplative and there is a calmness about this tree-dweller, even though the branch it sits on dips alarmingly under its weight.

It is big and solid with warm grey fur on its back, and black on face, paws and hind feet. Still watching us, the tree-roo reaches back and scratches its side with massive claws. With its long feet, round ears and short muzzle, it looks like a cross between a wallaby and a sun-bear. It might not be the most beautiful mammal – who’s to judge, anyway? – but it is one of the most remarkable.

Feeling elated, privileged and a little bit emotional, we leave the tree-roo to finish its meal in peace. Sightings are rare. No one knows how many Lumholtz’s tree-kangaroos live on the Atherton Tablelands, and even in the locations where they are reported most frequently, luck plays a major part in spotting one.

Malanda Falls conservation park receives about 40,000 visitors a year. In the breeding season, when tree-kangaroos are more active and less wary, one to two sightings a week are reported to the visitors centre. At other times, weeks pass without a notification.

Back at Yungaburra, we set out for a walk along Peterson Creek, where another sighting could be possible, with a good chance of seeing a platypus in the slow-flowing waters too.

But as we pass the rambling, Federation-era Yungaburra hotel, which is almost as big as the pub in Malanda, we have another idea.

Parking on a road lined with hanging baskets of pink and white impatiens, we duck inside. There we raise a glass to the elusive Lumholtz’s tree-kangaroo, still hanging on.

Getting there

Driving is the easiest way around this area. The closest airport to Yungaburra is Cairns, about 70 minutes drive via Gordonvale on the Gillies Range Road or 90 minutes by car via Kuranda on the Kennedy Highway.

Yungaburra, Malanda and surrounds offer a variety of accommodation, and places to buy coffee and scones.

Wildlife tours are also available from guides on the Atherton Tablelands and in Cairns.