What is a tree kangaroo?
Hidden high in the treetops of rainforests in northeastern Australia and New Guinea are the tree kangaroos. It may be surprising to think of a kangaroo living in the trees, but there was once a time when all kangaroos resided in trees. As the species evolved, they migrated down to become ground kangaroos. Over millions of years, though, some returned to the trees and adapted to the arboreal lifestyle.
Though tree kangaroos are one of the lesser-known species of Australia, they are by no means less fascinating. Unlike their ground-dwelling kangaroo relatives, tree kangaroos are well adapted to thrive in the dense canopy of tropical rainforests. Although there are 14 species of tree kangaroos, each with unique characteristics, these marsupials typically have long and muscled arms, curved and sharp claws, as well as large and padded back feet, which mould around trees to aid with climbing. A distinct characteristic of tree kangaroos are their long, bushy tails, which they often push against tree trunks for balance and stability.
The size, weight, and fur colour of a tree kangaroo can vary based on the species. Lumholtz’s tree kangaroo usually has reddish-grey fur, weighs about seven kilograms (15 pounds) and stands around 56 centimetres (22 inches) tall. Bennett’s tree kangaroo, on the other hand, has a grey-brown coat with a black underside, weighs up to 14 kilograms (30 pounds), and stands 76 centimetres (30 inches) tall.
Tree kangaroos are herbivores. Their diet is primarily made up of leaves, roots, seasonal fruits, and bark. They spend hours foraging in their arboreal habitat for foliage and fruits, though they will sometimes visit the ground in search of more food.
The tree kangaroo is a solitary creature, and these macropods don’t typically form strong social bonds. Instead, male tree kangaroos interact with several females, and females remain independent from males. They usually only come together during mating periods. While little is known about the specific breeding habits of tree kangaroos, they’re thought to be opportunistic breeders rather than seasonal ones.
Female tree kangaroos birth one offspring at a time, after a gestation period of approximately 44 days. A newborn tree kangaroo—known as a joey—resembles a foetus and is no bigger than a bean. Tree kangaroos are marsupials, meaning the females don’t develop a placenta and instead carry their young around in a pouch on their abdomen. These pouches contain teats, from which the joeys nurse.
A joey stays inside its mother’s pouch for around nine months, followed by a weaning period of another one to two months during which it hops in and out of the pouch. Despite their preferred solitude, female tree kangaroos are thought to form strong social bonds with their offspring. The joeys stay with their mothers until they reach sexual maturity at around two years old.
Tree kangaroos play an important role in maintaining the ecological balance of their arboreal habitats. As they move through the trees, they aid both pollination and seed dispersal, which is critical to the regeneration, functioning, and resilience of forests. This is particularly important given how beneficial rainforests are to the Earth’s ecosystem. Not only do they capture and store carbon, helping mitigate climate change, but they’re also critical to local communities, as these ecosystem services help provide food, water, and shelter.
Despite their significance to the health of our world’s rainforests, tree kangaroos face threats to their survival. Habitat destruction—as a result of deforestation, hunting, and human encroachment—poses challenges for the species.
To safeguard these fascinating animals and the biodiversity of rainforests, more conservation efforts are needed. Learn more about the tree kangaroos and how we can help them.
What is a tree kangaroo’s scientific name?
Tree kangaroos belong to the genus Dendrolagus. Part of the Macropodidae family, the genus Dendrolagus is the only arboreal group of kangaroos—meaning they’re the only ones that live in trees.
Dendrolagus is split into two main divisions. There are the more ancestral species, which include the two Australian species (Bennett’s tree kangaroos and Lumholtz’s tree kangaroos), which are known for their long feet. There are also shorter-footed species that are more evolved than the former, which include the 12 species from New Guinea and Indonesia.
There are currently 14 known species of tree kangaroos:
- Huon tree kangaroo (Dendrolagus matschiei)
- Doria’s tree kangaroo (Dendrolagus dorianus)
- Lowlands tree kangaroo (Dendrolagus spadix)
- Goodfellow’s tree kangaroo (Dendrolagus goodfellowi)
- Tenkile tree kangaroo (Dendrolagus scottae)
- Vogelkop tree kangaroo (Dendrolagus ursinus)
- Wondiwoi tree kangaroo (Dendrolagus mayri)
- Seri’s tree kangaroo (Dendrolagus stellarum)
- Grizzled tree kangaroo (Dendrolagus inustus)
- Lumholtz’s tree kangaroo (Dendrolagus lumholtzi)
- Bennett’s tree kangaroo (Dendrolagus bennettianus)
- Golden-mantled tree kangaroo (Dendrolagus pulcherrimus)
- Dingiso tree kangaroo (Dendrolagus mbaiso)
- Ifola tree kangaroo (Dendrolagus notatus)
Are tree kangaroos endangered?
According to the IUCN Red List, tree kangaroos range from near threatened to critically endangered across the various species. Here are the different tree kangaroos’ IUCN classifications:
- Near threatened: Lumholtz’s tree kangaroo, Bennett’s tree kangaroo
- Vulnerable: Doria’s tree kangaroo, lowlands tree kangaroo, Vogelkop tree kangaroo, Seri’s tree kangaroo, grizzled tree kangaroo
- Endangered: Huon tree kangaroo, Goodfellow’s tree kangaroo, dingiso tree kangaroo, ifola tree kangaroo
- Critically endangered: Tenkile tree kangaroo, Wondiwoi tree kangaroo, golden-mantled tree kangaroo
Where do tree kangaroos live?
Tree kangaroos are found in the rainforests of Australia, New Guinea, and Indonesia. Their habitats range from lowland tropical forests to mountainous regions, where there is dense vegetation and plenty of tree cover. Here’s a breakdown of where you can find each of the tree kangaroo species:
- Australia: Bennett’s tree kangaroo and Lumholtz’s tree kangaroo
- Papua New Guinea: Ifola tree kangaroo, Tenkile tree kangaroo, Doria’s tree kangaroo, lowlands tree kangaroo, and Huon tree kangaroo
- Indonesia: Dingiso tree kangaroo, Vogelkop tree kangaroo, and Wondiwoi tree kangaroo
- Both Papua New Guinea and Indonesia: Seri’s tree kangaroo, grizzled tree kangaroo, golden-mantled tree kangaroo, and Goodfellow’s tree kangaroo
These rainforests provide the perfect home for tree kangaroo’s arboreal lifestyle. Compared to kangaroos found on the ground, tree kangaroos have longer forearms and shorter hind legs. Unlike terrestrial kangaroos, tree kangaroos can move their hind legs separately, which aids them in their climbing movements, as well as hopping. Tree kangaroos also have rough pads on their fore and hind feet, as well as long claws which help them grip trees.
Terrestrial kangaroos’ tails play a role as a fifth appendage, but tree kangaroos’ tails have evolved to lose this function. Instead, these slightly shorter tails help them balance in tall trees.
Tree kangaroos face several threats to their survival, from hunting and deforestation to agricultural expansion and climate change. Sadly, the golden-mantled tree kangaroo is one of the most endangered mammals in the world.
In some regions, tree kangaroos are hunted for their meat or fur. For many species, this threat alone has contributed to a sharp decline in their populations. Despite legal efforts to protect tree kangaroos, illegal hunting practices still threaten their survival.
Rainforests are often targeted by humans as areas for logging or to build roads. As a result, tree kangaroos’ rainforest habitat is shrinking. As trees are cleared, tree kangaroos lose their homes and food sources. It also leaves them exposed to predators.
Agricultural expansion has led to the conversion of rainforests into agricultural land. On a smaller scale, tree kangaroo habitat is replaced with coffee plantations or rice and wheat cultivations. On a larger scale, huge areas of rainforests are cleared for palm oil plantations.
Natural disasters and climate change
Climate change has a huge impact on the habitats of tree kangaroos. Prolonged periods of drought can cause forest wildfires to catch and spread, which is a major threat to their larger ecosystem. During a severe El Niño episode in 1997, extensive wildfires devastated the upper montane forests across significant parts of the Sarawaged and Finisterre Ranges. This event led to a substantial reduction in suitable habitats for tree kangaroos.
As climate change continues to become a bigger issue for the planet, it’s expected that there will be an increase in both the frequency and intensity of these wildfires.
Which country is the natural home of tree kangaroos?
Tree kangaroos are native to three countries: Australia, Papua New Guinea, and Indonesia. Land bridges which once connected these islands allowed animals to migrate between them, leading to very similar species evolving in all three countries.
- Some tree kangaroo species are found in both Papua New Guinea and Indonesia, including Seri’s tree kangaroos, grizzled tree kangaroos, golden-mantled tree kangaroos, and Goodfellow’s tree kangaroos.
- Some tree kangaroo species are very closely related to those above, except that they are native only to New Guinea, including Ifola tree kangaroos, Tenkile tree kangaroos, Doria’s tree kangaroos, lowlands tree kangaroos, and Huon tree kangaroos.
- Then there are those who are still closely related but live in Indonesia, including Dingiso tree kangaroos, Vogelkop tree kangaroos, and Wondiwoi tree kangaroos.
- Finally, there are the tree kangaroos that are unique to Australia, including Bennett’s tree kangaroos and Lumholtz’s tree kangaroos.
How many species of tree kangaroos are there?
There are 14 species of tree kangaroos:
- Huon tree kangaroos (Dendrolagus matschiei)
- Doria’s tree kangaroos (Dendrolagus dorianus)
- Lowlands tree kangaroos (Dendrolagus spadix)
- Goodfellow’s tree kangaroos (Dendrolagus goodfellowi)
- Tenkile tree kangaroos (Dendrolagus scottae)
- Vogelkop tree kangaroos (Dendrolagus ursinus)
- Wondiwoi tree kangaroos (Dendrolagus mayri)
- Seri’s tree kangaroos (Dendrolagus stellarum)
- Grizzled tree kangaroos (Dendrolagus inustus)
- Lumholtz’s tree kangaroos (Dendrolagus lumholtzi)
- Bennett’s tree kangaroos (Dendrolagus bennettianus)
- Golden-mantled tree kangaroos (Dendrolagus pulcherrimus)
- Dingiso tree kangaroos (Dendrolagus mbaiso)
- Ifola tree kangaroos (Dendrolagus notatus)
What do tree kangaroos look like?
Tree kangaroos have distinct physical characteristics that help them to navigate their habitat in the rainforest canopies. Their forelimbs are notably longer than those of their terrestrial counterparts, while their hindlimbs are shorter and able to move independently. This helps them to be more agile when climbing trees. Their feet are also well adapted for climbing, with rough pads that provide excellent grip, as well as elongated claws to help them climb. Their shorter tails help them maintain their balance in the treetops.
The markings and colouration of tree kangaroos differ across the species. The Goodfellow’s group (which includes Goodfellow’s tree kangaroos, Huon tree kangaroos, and lowlands tree kangaroos) typically have reddish coats with varying dark markings, while the Doria’s group (which includes Doria’s tree kangaroos and Tenkile tree kangaroos) tend to be browner with minimal distinct body markings.
Are tree kangaroos related to kangaroos?
Yes, tree kangaroos are part of the macropod family of marsupials, which also includes kangaroos and wallabies. The macropod family is characterised by animals with generally large feet, strong hindlimbs, long tails, thin necks, relatively small heads, prominent ears, and a herbivore diet.
Both tree kangaroos and kangaroos used to reside in trees. As they evolved, they all climbed down to live on the ground. However, tree kangaroos returned to the trees, leaving terrestrial kangaroos below. They have since evolved into 14 different species.
Can kangaroos climb trees?
While the terrestrial kangaroo can’t climb trees, tree kangaroos can.
How long do tree kangaroos live?
Tree kangaroos are known to live between 15 and 20 years.
Why are tree kangaroos endangered?
Tree kangaroos are endangered due to a number of threats. In some regions, they are illegally hunted for their meat and fur. Their populations are also under pressure from the threat of deforestation, which is caused by human activity such as logging, infrastructure, or agricultural practices. Large areas of their rainforest habitat have been cleared to make way for these human activities, which leads to loss of habitat and therefore loss of shelter and food.
Climate change has also contributed to the endangerment of tree kangaroos. Wildfires caused by long periods of drought destroy the rainforests in which tree kangaroos live, leading to a decline in their populations.
How many tree kangaroos are left?
The population of tree kangaroos varies across the 14 total known species. Of the most endangered tree kangaroo species, there are only 40 mature Wondiwoi tree kangaroos, 200 mature tenkile tree kangaroos, and 500 golden-mantled tree kangaroos left.
Conservation efforts are critical for protecting these animals. Tree kangaroos play a vital role in the rainforest ecosystem by pollinating and dispersing seeds as they move through the canopies of the trees. This helps regenerate rainforests, which are an important source of carbon sequestration and therefore key to combating climate change.
How can you help?
Tree kangaroos are threatened by hunting practices, deforestation, agricultural expansion, and climate change. Consider supporting conservation efforts to help protect them.