Tree Kangaroo

Returned to the trees

Tree kangaroos are macropods — the family that includes kangaroos, wallabies, and quokkas — that returned to an arboreal lifestyle from terrestrial ancestors. This evolutionary reversal required significant anatomical change. Unlike ground kangaroos, tree kangaroos can move their hind legs independently (ground kangaroos cannot), allowing them to walk in branches. Their forelimbs are longer and stronger, their feet shorter and broader, and their claws curved and roughened for gripping bark.

Arboreal adaptations

Tree kangaroos move through the canopy by climbing, jumping between branches, and descending headfirst using their forelimbs. The long tail provides counterbalancing but cannot grip (it is non-prehensile). When threatened, tree kangaroos drop from the canopy — falls of up to 18 metres have been recorded with no apparent injury. The hindquarters land first, cushioned by the powerful leg muscles. On the ground, their locomotion is awkward and hopping; in trees, they are surprisingly agile.

New Guinea diversity

The majority of tree kangaroo species live in New Guinea, where they occupy a range of forest habitats from lowland rainforest to montane cloud forest above 3,000 metres. Goodfellow’s tree kangaroo and the Matschie’s tree kangaroo are among the most striking, with rich chestnut and gold colouring. Many New Guinea species are poorly known scientifically. The 1990s saw the discovery of new species as remote highland regions were explored.

Threats

Tree kangaroos are threatened by hunting — they are a traditional food source for forest peoples of New Guinea — and by habitat loss. Logging, forest clearance for palm oil and agriculture, and mining are reducing forest cover across New Guinea. Several species are listed as Endangered. In Australia, the Lumholtz’s and Bennett’s tree kangaroos in Queensland are affected by rainforest clearing and vehicle strikes.