Years ago, I watched a BBC television series called ‘River Journeys’. It did what it said on the tin: the programme accompanied adventurers, writers, journalists, and academics on journeys along rivers. William Shawcross made his way up the Mekong, Germaine Greer travelled the Sao Francisco, Russell Braddon the Murray. In the opening episode, explorer Christina Dodwell paddled down the threshing waters of the Wahgi River in Papua New Guinea. To get to the headwaters of the Wahgi, which rises in the Central Highlands and flows south, Dodwell first sailed up the Sepik River. The Sepik also rises in the Highlands, but runs in the other direction to open into the Bismarck Sea. At 1,125 kilometres, it is the longest river in New Guinea.
Because I am neither an intrepid white water rafter nor particularly adventurous, what caught my imagination was not the terrifying Wahgi but the Sepik winding its way through the lowlands. I desperately wanted to see this river and its wildlife. The programme went to air in 1985. Thirty-four years later, thanks to my friend Tonia Cochran who runs Inala Nature Tours, I finally went on my own river journey along the Sepik.
We flew from Mount Hagen across the rugged spine of the island to land at a short airstrip cut out of the forest. From there, we took a boat upriver, past tiny villages and sago palm swamps, around floating islands made of cordylines and sandbanks where Great-billed Herons hunted in the shallows. On mooring, we clambered onto the back of a truck and bumped and jolted along a muddy track to our accommodation at the top of a hill. Our rooms overlooked the river and beyond to rainforest that extended to the horizon.
On our first day, we saw Blyth’s Hornbills, Black Sunbirds, and a dozen different types of parrots from Palm Cockatoos to pygmy-parrots. The evening ended with a spectacular tropical thunderstorm. Lightning flashed across the tree tops.
I am a systematist and biogeographer. My interest is the way in which geography influences the evolution of species. Alfred Russel Wallace was the first to investigate this relationship methodically, outlining the patterns in ‘The Malay Archipelago’ (1869) and the two volumes of ‘The Geographical Distribution of Animals’ (1876) and delving deeper in subsequent publications. Wallace spent time at Manokwari on the Bird’s Head Peninsula and on the islands to the west, collecting and cataloguing the fauna. He noted the link between the animals and plants of New Guinea and Australia, which arose from the geological connection between the two land masses, and the exuberant diversity of some faunal groups in the highlands. Although birds of paradise and tree kangaroos live in both locations, only four species of the former and two of the latter occur in Australia. There are many more birds of paradise and tree roos in New Guinea. It is an evolutionary hotspot driven by geological and ecological complexity. How could I resist it?
The Sepik and its tributaries form the road system in this part of the country. Each day we headed out on the water to look at wildlife. Scrambling up a mud bank, we watched a Twelve-wired Bird of Paradise land in a dead tree and flutter his short black wings and long yellow skirt while the ‘wires’ flicked around him like a bad hair day. In the rainforest, a brilliant orange King Bird of Paradise fed on fruit above our heads. From the boat, Chris, our guide, and the crew found us Papuan Frogmouths, fruit-doves and imperial-pigeons, Golden Mynas, and two Victoria Crowned Pigeons perched on a bare branch high above the water. In one of his scientific papers, Wallace quoted William Dampier’s 1699 description of a crowned pigeon:
One of my men killed a stately land-fowl, as big as the largest dunghill-cock. It was of a sky-colour; only in the middle of the wings was a white spot, about which were some reddish spots. On the crown it had a large bunch of long feathers, which appeared very pretty. His bill was like a pidgeon’s [sic].
These were the only wild crowned pigeons we saw on the trip. Even from a distance, they were remarkable and beautiful birds, and a privilege to observe.
While I could muddle through the birds, the flora along the Sepik was completely beyond my knowledge — except for one flower. Sago palm swamps and riverine rainforest are the natural habitat of Dendrobium lasianthera Sepik Blue, a spectacular purple orchid with helical petals. The species was first collected in the northern lowlands by Wilhelm Stüber, who sent plants to botanical gardens and orchid fanciers. Given his efforts, he had hoped that it would be named after him. An orchid breeder obliged, submitting a description of Dendrobium stüberi to ‘The Orchid Review’. But the species had already been described — from material Stüber had collected and distributed some years before. Johannes Jacob Smith had named it D. lasianthera in 1932 and that had priority. Stüber died without an orchid bearing his name.
Christina Dodwell’s last stop on the Sepik was Kraimbit village, only 15 kilometres from where we were staying. After Kraimbit, she travelled overland to the Wahgi for the second part of the journey. We took the easier option and flew back to Mount Hagen, and from there home to Australia. I was already planning my return trip while we waited for the plane.
I think of our friends on the Sepik and in Mount Hagen and the wonderful time we spent in their company. I hope we will all meet again.