Black tree kangaroo (Dendrolagus ursinus)

Also known as: Vogelkop tree-kangaroo, white-throated tree kangaroo
Synonyms: Dendrolagus leucogenys
  
French: Dendrolague Noir
Spanish: Canguro Arborícola Negro
KingdomAnimalia
PhylumChordata
ClassMammalia
OrderDiprotodontia
FamilyMacropodidae
GenusDendrolagus (1)
SizeHead-body length: 50 – 82 cm (2)
Tail length: 41 – 94 cm (2)
Weight8 kg (3)

Classified as Vulnerable (VU) on the IUCN Red List (1) and listed on Appendix II of CITES (4).

The black tree kangaroo has the dubious honour of being one of the ‘tastier’ marsupials discovered by early Dutch explorers on the island of New Guinea (5). The first part of its scientific name, ‘dendron’, means tree in Greek while ‘lagus’ means hare (5) (6); it is thought that it was given the ‘lagus’ part of this name due to its gastronomic similarity to hare rather than for its hopping style of locomotion (5) (7). Sadly, this name also serves as a potent reminder of one of the main threats to this exceptional creature: hunting by humans for food (1) (5) (8).

The black tree kangaroo is easily recognised by its long, tufted ears which are unique amongst tree kangaroo species (6). Lustrous, long, black fur covers the back and tail, while the fur on the underside is coffee-coloured.  Its distinctive face is more brown, with white, or sometimes red, cheeks and a white throat, explaining why it is also commonly called the white-throated tree kangaroo (5) (6). The fur on top of the shoulders grows in a spiral pattern or whorl, which is thought to protect the face by channelling rainwater away from the head (5). As a member of the short-footed group of tree kangaroos (6), the black tree kangaroo is well adapted to an arboreal lifestyle. It has sturdier arms and shorter, wider feet than its ground-dwelling relatives with roughened pads for gripping, well-developed curved claws on its front paws to aid climbing, and a long, white-tipped tail which acts as a counter-balance while in the trees (5) (6).

The black tree kangaroo is found exclusively in the north-western region of the island of New Guinea, Indonesia, where it is restricted to the Vogelkop or “Bird’s Head” peninsula (so-called because of its resemblance to a bird’s head) and the Fak Fak peninsula (1) (8).

Historical reports indicate that this species once had an extensive range from lowland forest at sea-level to high mountainous rainforest (1) (6). However, due to the threats it faces at lower elevations, it is today only found between 1,000 and 2,500 metres above sea level, in tropical forest (1).

Unfortunately, since its discovery in the early 19th century very little information has been gathered about this enchanting species. It is known to be mostly solitary and nocturnal, emerging after dark to feed on its preferred food of leaves and fruit (5) (6). Some reports suggest that a large proportion of the black tree kangaroo’s diet may consist of fruit; this would make them unique amongst their tree kangaroo relatives who are predominantly foliovores (leaf-eaters) (6). All tree kangaroos leave the safety of the trees at some point to forage on the ground, but the amount of time spent on the ground tends to vary dramatically between species (5). While they move through the treetops with superb agility - with some tree kangaroo species being able to drop to the forest floor from heights of 7 to 15 metres without injury (2) (7) - once on the ground their movements can be slow and clumsy, travelling with a bipedal (two-footed) hopping motion reminiscent of the larger, ground-dwelling kangaroos (9).

It is probable that the black tree kangaroo, like other tree kangaroos, can mate throughout the year, giving birth to a single, under-developed joey after a gestation period of around 32 days (2). The tiny newborn is vulnerable without fur or sight, but has well-developed forelimbs that enable it to climb up its mother’s fur into the protective environment of her pouch (10). The joey will continue to grow and develop within the warm, safe pouch for a further 300 days or more, gaining all the nutrients it requires from its mother’s milk (2). Tree kangaroos reach sexual maturity at around two years of age and can live as long as 20 years in captivity (3).

The black tree kangaroo is currently under threat from hunting by local people for its meat and has been classified as Vulnerable to extinction on the IUCN Red List due to the fact that its population numbers have declined by at least 30 percent in the last 30 years and continue to do so (1). This reduction in population is evident by its disappearance from the more densely populated areas of the Vogelkop Peninsula, within the Arfak montane forests for example, so that its range is now limited to areas with little or no human presence (1) (6) (8).

Hunting pressure is unfortunately not the only threat faced by this beautiful marsupial. Increased logging and forest clearance for agricultural purposes has meant that the black tree kangaroo has lost a considerable part of its habitat over the last 60 to 70 years, with a resultant decline in its numbers (1) (8).

Although there are no specific conservation measures in place for this species, the region in which they are found contains ten protected areas which make up 52 percent of the Vogelkop montane rainforests (8). When compared to the rest of New Guinea, these forests are in relatively pristine condition and with continued conservation efforts from organisations such as WWF and the Tenkile Conservation Alliance (established primarily for the Scott’s and golden-mantled tree kangaroos) (11), it is hoped that increased awareness and protection can be given to these enigmatic and captivating marsupials.

To learn more about the conservation of tree kangaroos see:

 To learn about wildlife conservation in New Guinea see:

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk

  1. IUCN Red List (March, 2010)
    http://www.iucnredlist.org
  2. Burton, M. and Burton, R. (2002) International Wildlife Encyclopaedia. Marshall Cavendish, Tarrytown, New York.
  3. AnAge: The Animal Ageing and Longevity Database (October, 2009)
    http://genomics.senescence.info/species
  4. CITES (March, 2010)
    http://www.cites.org
  5. Martin, R. (2005) Tree-Kangaroos of Australia and New Guinea. CSIRO Publishing, Collingwood, Australia.
  6. Flannery, T.F., Martin, R. and Szalay, A. (1996) Tree-Kangaroos: A Curious Natural History. Reed Books, Melbourne, Australia.
  7. Procter-Gray, E. and Ganslosser, U. (1986) The individual behaviours of Lumholtz’s tree-kangaroo: repertoire and taxonomic implications. Journal of Mammalogy, 67(2): 343-352.
  8. Wikramanayake, E., Dinerstein, E. and Loucks, C.J. (2002) Terrestrial Ecoregions of the Indo-Pacific. A Conservation Assessment. Island Press, Washington DC.
  9. Burnie, D. (2004) Animal. Dorling Kindersley, London.
  10. Macdonald, D. (2006) Encyclopaedia of Mammals. Oxford University Press, Oxford.
  11. Tenkile Conservation Alliance (October, 2009)
    http://www.tenkile.com