Kangaroos in trees?!

Skyrail Nature Diary: April 2007

Whilst it might be hard to believe, there are actually two types of kangaroos living in the tree tops of Australia’s Tropical Rainforests.

The Bennett’s Tree Kangaroo (Dendrolagus bennettianus) and Lumholtz’s Tree Kangaroo (Dendrolagus lumholtzi) are both fairly evasive critters, rarely seen, and only found in very restricted areas of the World Heritage rainforest.

The Bennett’s, the larger of the two, was first seen in 1872; the first live specimen was captured near the Daintree River and sent to the Queensland Museum for identification in 1886. Today, the Bennett's Tree Kangaroos live in a small area, at high and low altitudes, north of the Daintree River.

Subsisting almost entirely on a diet of leaves from rainforest trees and vines, the Bennett’s is a solitary creature, preferring its own company to living in large communities.

They spend their days sleeping amongst the dense rainforest canopy, with their black chests, stomachs and underside colouring making it very difficult to spot them when searching from the ground. The males, which are larger than the females, can weigh up to 14kg and defend their territories from other males.

The Lumholtz’s Tree Kangaroos have a slightly larger distribution than the Bennett’s, occupying an area of montane rainforest accounting for approximately 5,500 square kilometers. The Lumholtz’s are generally found at higher altitudes, between 300m and 1,600m, and although they are also solitary animals, they can sometimes be found in small groups of up to three or four adults.

The Lumholtz’s are the smallest of all the known Tree Kangaroo species (including the several that live in Papua New Guinea), with males averaging 7.2kg and females 5.9kg.

The physical characteristics of both the Bennett’s and Lumholtz’s Tree Kangaroos are similar. Both have exceptionally long tails, up to 1m, with strong forelimbs and broader hind feet. They have curved claws on their feet and paws, and ‘spongy’ soles and palms, which help with balancing, gripping and climbing. They both stand approximately 60cm tall and both spend the majority of their time in the tree tops, eating leaves and the occasional rainforest fruit or flower.

However, whilst the Bennett’s has dark underside features, the Lumholtz’s can be identified by its creamy coloured chest and stomach, black feet and grey back with black tips.

Like other kangaroo species, the tree kangaroos have pouches to raise their young in. Although neither the Bennett’s nor the Lumholtz’s appear to have a definite breeding season, both seem to produce one offspring per year. The baby tree kangaroos of both species will spend approximately eight months in the pouch, and a further two years with their Mother, before separating.