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Sahul includes New Guinea and Australia |
New Guinea is the world’s second largest island* after Greenland and the world’s third largest rainforest after the Amazon and the Congo. It is also the least explored. This vast rainforest spans both Papua New Guinea (PNG) -the eastern half, and Indonesian Papua -the western half, covering roughly 786,000 km.² Despite occupying less than 1% of Earth’s land area, it harbours 5–10% of global biodiversity, with extraordinary levels of endemism and ecological diversity, by which we mean living in specific elevations, different types of rainforest and so on..
[* Sorry folks. Most Geographers do not think of Australia as an island because it's about four times bigger than Greenland, has its own tectonic plate and a unique suite of animals which are found nowhere else].
At a time when other great forests like the Amazon and those in Indonesia begin calling a halt to deforestation, it is precisely these hitherto almost intact and less well known forests such as those in the Congo and here, which are falling victim to the loggers, the axe, chainsaw or machete, and much faster than before.
As with neighbouring Wallacea, long isolation and quirks of geography have contributed to its assemblage of animals and plants. Thanks to the Timor Trough, New Guinea has echnidnas and tree kangaroos instead of monkeys and lizards. Originally connected to both Australia and thus Tasmania, the closing of land bridges after the last Ice Age about 8- 10, 000 million years ago, separated these landmasses too and stranded many of its species, which then went on to evolve in their own way.
Several of New Guinea's mountains which run 1600 km down the central 'spine' of its ducklike shape, are over 4,000 metres high. They provide highly specialised habitat such as montane and cloud forests for some species. This fragmentation has also contributed to making Papua New Guinea one of the world's 17 megadiverse hotspots, and home to around 10% of its vertebrates.
🦜 Endemic Species & Ecological Niches Taxonomic Group |
Number of Different Types | % Endemicity | Habitat / Elevation |
---|---|---|---|
Mammals | 295 | 31% | Mid to high elevation forests; canopy and understory |
Birds | 740+ | 15% | Montane forest, cloud forest, lowland swamp |
Amphibians | 426 | 76% | Leaf litter, mossy forest floor, below 2000 m |
Reptiles | 415 | 29% | Riverbanks, lowland rainforest, woodland edges |
Plants | 13,800+ | 16.5% | Epiphytes and orchids in montane/cloud forests; figs from lowland to upland |
Insects | 150,000+ | Unknown | 500–1500 m; canopy, understory, and leaf litter zones |
Remarkable Fauna
- Birds-of-Paradise: With extravagant plumage and elaborate courtship dances, these birds are icons of New Guinea’s forests. There are over 40 species, many of them endemic.
- Queen Alexandra’s Birdwing: The largest butterfly in the world, with a wingspan reaching 28 cm, found only in PNG’s Oro Province.
- Southern Crowned Pigeon: The largest pigeon on Earth, with a regal crest and deep blue plumage — a living relic of Gondwanan grandeur.
- Cassowary: A prehistoric-looking, flightless bird with a vivid casque and dagger-like claws. It plays a vital role in seed dispersal.
- Long-beaked Echidnas: Monotremes that resemble spiny anteaters, including the elusive Zaglossus attenboroughi, named after Sir David Attenborough.
- Cuscus: Arboreal marsupials with large eyes and prehensile tails, often overlooked but ecologically important.
Creature Feature
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Common Green Birdwing Butterfly (Ornithoptera priamus) - not the rarest butterfly, but at least one not yet endangered |
© Photo: |Under Licence CC N0 | Source: PxHere
🌿 Remarkable Flora
- Araucaria Trees: Towering conifers reaching up to 70 meters, among the tallest tropical trees globally.
- Orchids: PNG hosts thousands of orchid species, from lowlands to montane forests and many of them are endemic
- Sago Palm: A cultural and ecological keystone — used for food, building, and habitat structure in lowland swamps.
- Nothofagus (Southern Beech): A Gondwanan genus found in PNG’s montane forests, linking it biogeographically to Tasmania, New Zealand and South America and dating from 118 million years ago when the continents were still joined together.
- Some of New Guinea's 2000 tree ferns such as the slender tree fern (Cyathea cunninghamii) and its 800 relatives and the soft tree fern (Dicksonia antarctica) with around 25 subspecies also date from this era and are shared with Tasmania, mainland Australia and New Zealand. Their common lineage goes back 400 million years, even before the dinosaurs.
- Moss Forests: Above 2,000 m, cloud forests teem with epiphytes,
fungi, and tree ferns, creating a surreal, mist-shrouded ecosystem.
- Almost as startling as the diversity of plants and animals, is New Guinea's cultural diversity. There are over 1,000 distinct cultural groups, each with its own customs, art, music and social structures.
These aren’t just variations — they’re deeply rooted identities shaped by
geography, ancestry, and spiritual beliefs. PNG is home to over 830–850 living
languages, representing about 12% of the world’s total. They involve dozens of language families with many spoken by just a few hundred
people.
Threats
- Deforestation
- Industrial logging, road-building, and biofuel
plantations are carving into ancient landscapes, especially on the
Indonesian side. There are no less 194 forest concessions and companies in play and most of them are foreign owned. Logging concessions cover 14.9 million ha,
with PNG being the world’s largest exporter of tropical timber.
- Mining, particularly open-pit operations like the Grasberg and Ok Tedi mines, has resulted in:
Wildlife trafficking threatens rare species—from iconic birds like cockatoos and lories to precious agarwood trees. It is the second biggest cause of species decline after habitat destruction. Like Australian Aborigines, some New Guinean tribes also had strong taboos and myths about not taking wildlife from certain places - 'sacred sites' as it were. These had enabled their Australian counterparts to survive over 60,000 years in a very harsh environment. We need to bring this idea back so that wildlife will always have a place to replenish itself.
Climate change is already making itself felt in Papua New Guinea, with more frequent and intense weather events - heavier rainfall, flooding, cyclones, rising temperatures, some sea level rise, and severe droughts during El Niño years. It may also have contributed to the recent landslide in Enga Province, in which an estimated 670 people died and some 7,800 were displaced.
Secondary problems which flow from warming and or weather extremes include declining water quality and quantity, increases in waterborne diseases and reduced crop yields.
New Guinea’s Disappearing Glaciers
At the start of the 21st century, New Guinea had six tropical glaciers clustered around its highest peak Punjak Jaya in Papua Province, Indonesia.
By November 2023, only one glacier remained - the Carstensz Glacier, already greatly diminished and expected to disappear entirely by 2026, or possibly earlier depending on the effects of El Niño and global warming. The loss of these glaciers is not only symbolic—it may also exacerbate regional warming, as the loss of light reflective ice surfaces accelerates heat absorption in the surrounding landscape.
Conservation Efforts
Despite its high biodiversity and importance as a largely intact forest and major carbon sink, only about 4.8% of Papua New Guinea’s land area was formally protected in 2022, well below the international target of 17%. Some sources say it’s even lower -as little as 1.6% depending on how areas are classified. Papua New Guinea’s new Protected Areas Act (2024) aims to protect 30% of land and sea by 2030.
- Progress:
- First comprehensive legal framework for protected areas.
- Empowers customary landowners to designate and manage conservation zones.
- Establishes a Biodiversity and Climate Task Fund to support local initiatives.
- Challenges:
- Less than 4% of land and 1% of sea currently protected.
- Communities remain skeptical due to past failures and lack of visible benefits.
- Implementation in rural areas is slow, and funding remains limited.
On the Indonesian side, things look somewhat better with protected areas increasing to approximately 20% in 2024 up from 12 -15% of the land area protected in 2018. However, according to recent research, even if managed effectively, they would still not adequately protect the full range of species, system functions and processes.
Indonesia’s Manokwari Declaration (2018) aims to protect 70% of forest cover in Papua and West Papua provinces. Although policy formalisation has advanced, with conservation zoning and green development plans, implementation challenges persist amid land tenure complexities and limited funding.
- Challenges:
- Limited capacity-building within provincial governments.
- Protected forest areas were reduced in zoning revisions, while agricultural zones expanded.
- Illegal logging and palm oil concessions continue, even in protected zones.
- Enforcement is patchy, and transparency tools like the Papua Atlas are still gaining traction.
Region | Protected Area Coverage | Notes |
---|---|---|
Papua New Guinea 🇵🇬 | ~4.8% | Mostly community-led; under-resourced and fragmented |
Indonesian Papua 🇮🇩 | ~12–15% | Larger area; weak enforcement and staffing challenges |
Global Aichi Target 🌍 | 17% | Benchmark for terrestrial protection under CBD goals |
Meanwhile, much of the conservation work is being left to individual communities working with various international organisations. Some examples follow.
- In the Torricelli Mountains in the far north
west of Papua New Guinea and home to three species of tree kangaroo, including the critically endangered tenkile and weimang and a northern glider (Petaurus
abidi) which is restricted to and area of less than 100 km,²
the Tenkile Conservation Alliance (TCA) has
proposed a 185,000-hectare protected area, but it’s not yet legally
recognised.
- In the Huon Protected Area on PNG's East Coast, indigenous communities maintain traditional stewardship, but formal protections vary.
. The Papuan Forest Stewards Program and WWF’s Sahul Program focus on community-led conservation, blending traditional knowledge with biodiversity protection.Begun in 2005 and using UNESCO world’s best practice - the Papuan Forest Stewards are changing ideas about rural development. The program acknowledges that traditional owners of these forests have protected the region’s natural heritage for millenia and aims to build on this stewardship by helping interested communities with the conservation of their traditions and by partnering them with institutions dedicated to bio-cultural conservation.
It’s primary focus in New Guinea has been on conserving the Core – the Central Highlands, where four great rivers arise. Occupied by an isolated Hunter Gatherer tribe, The Hewa, and supported by international cultural and natural history institutions such as Harvard, The Smithsonian, The South Australia Museum and Conservation International, the Forest Guardians aim to create a locally managed conservation program through sharing of traditional knowledge and capacity building, so that this isolated forest community will have a pathway to a sustainable future.
The endangered long beaked echidna exists only in the alpine meadows above 3,666 metres in the humid mountains of the New Guinea Highlands and is often hunted for food using specially trained dogs. Their numbers are also threatened by logging of their habitat, mining and agriculture. Here the Papuan Forest Guardians have teamed up with researchers, SPOT Satellite Messenger and the Smithsonian Institute to track its numbers and put together a conservation plan using SPOT locator beacons.
Birdlife International is of course primarily concerned about New Guinea’s exceptional collection of birds, but of necessity this involves protecting their habitat too. To this end it is working with local communities to enable them to manage their forests more sustainably.
The previously mentioned Tenkile Conservation Alliance (TCA) in the Torricelli Mountains for example, is doing this through training and technical support from the University of Papua New Guinea. Another aspect involves enabling villages to trace their ancestry in order to establish clearer boundaries, sign landowner agreements and strengthen their ability to monitor and manage their own lands.Some landowners have since taken steps to end illegal logging and TCA has introduced new ways for villagers to earn a living – by raising chickens or growing rice and vanilla for example, instead of having to hunt endangered wildlife. Monitoring of tree kangaroos in the area helps to assess the health of the forest and guide land use planning and policy making.
The jewel in the crown of community – led conservation and known as the REDD QUEEN in New Guinea is perhaps the REDD+ Scheme taking place at April Salumei in the East Sepik region.
REDD by the way, stands for Reducing Emissions from Deforestation and Forest Degradation.
With climate funds from countries such as Denmark, Switzerland, Norway, Japan, Luxembourg and Spain, it is designed to protect 600,000 ha of rainforest which was previously earmarked for logging. It will prevent the release of 22.8 million tonnes of CO2* over its lifetime and protect the habitat of species such as tree kangaroos, birds of paradise, palm cockatoos and crowned pigeons.Sixty per cent of Carbon Credit offsets go to local landowners -15,000 people in 164 clans. The five -year development plan creates employment opportunities and reafforestation through the provision of 10,000 native eaglewood trees for sustaninable agriculture. Additional benefits for communities include the installation of 1,000 solar lamps to schools, clinics and homes and funding for 15 schools.
These are just some of the conservation measures being undertaken in New Guinea. Although progress is being made, the efforts are piecemeal and much more needs to be done if we are to protect this last great reservoir of biodiversity as well as maintain it as a bulwark against climate change.
What does it matter you ask, if some little known or unknown species disappears in a place we know hardly anything about? There are many answers to that question. From a moral perspective there are those who would argue that we should not leave the planet in worse shape than we found it and we owe it to our successors and the species themselves to keep as many of them going as we can. We are already presiding over a mass extinction crisis. Just ask the insects, the bees and the birds.
Pragmatists argue that we don't know which ones may yield the answer to other problems such as intractable diseases or plastic pollution - some fungi have been known to digest plastic, and we don't even know what's out there. Some think we should save species because there might be money to be made from them at some future date, yet the reasons are both more subtle and more far -reaching than that. Think of them as butterfly effects - small changes in distant places that can have profound consequences a long way away.
Butterflies are how the giant dipterocarps are fertilised because butterflies carry pollen from one place to another and between the trees and plants upon which smaller creatures feed. The birds spread fruit seeds throughout the forests and even distant islands. That peculiar pig in Sulawesi probably disturbs the leaf litter and tramples the seeds into the earth as well as fertilising them.
Take away one or two elements and that edifice collapses, along with the species that depend on it. Sun and wind dry the forest floor. Fires burn what were previously perpetually wet forests. Soils are exposed to the elements. They erode. Add an unprecedented rainfall and mountains collapse. When forests are lost, the capacity of the ecosystem to regulate climate is also diminished leading to more extreme weather and more instability. In time, whole regions could look like Central Australia or the ghost forests of Aralkum, something which happened in our lifetime. Arid. Infertile. Unable to capture water or return it to the skies, unable to grow crops or feed the people who depend on them.
These tropical forests we've talked about are our strongest defence against further climate change. Take them away or allow them to die by a thousand cuts and eventually we harm our own survival. The process is slow and imperceptible at first - a big tree here, another coupe, another river despoiled, and then feedback loops hasten their demise and ours.
As young climate activist Tangwa Abilu put it far more succinctly:
“Think the rainforest is just a distant wilderness? Think again.
ü It produces the oxygen we breathe
ü It stores carbon and fights climate change
ü It holds undiscovered medicines
ü It supports indigenous communities
Without these forests, humanity faces collapse. We depend on them more than we realise.
No rainforest? No future.”
Lots of help from Microsoft Copilot on this post as I knew shockingly little about our nearest neighbour. It has certainly been a interesting journey and I hope you found it so too.
Support the groups working towards raiforest survival in New Guinea. Read labels carefully and avoid those containing uncertified palm oil or tropical timber.
Next up: A little about Australia's dwindling tropical rainforests which are also part of Sahul and which once covered the entire country. They are also home to some of the world's oldest plants and animals. However, I do want to move on to Climate Change Adaption and Mitigation, so forgive me if I have to leave the temperate rainforests for another time.
* If you were wondering how they measure how much carbon is held in a forest, check out this short doco by DW here.
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