Bennett's tree-kangaroo, Dendrolagus bennettianus, is endemic to tropical rainforests in northeastern Queensland, Australia. Its range is very limited, extending from the Daintree River in the south to Mt. Amos in the north and Mt. Windsor in the west (Newell, 1999), an area covering less than 4000 square-kilometers (Martin, 1995).
Biogeographic Regions: australian (Native )
Though similar in overall form to kangaroos, wallabies, and other macropods, when compared with these terrestrial kangaroos, Dendrolagus has longer forelimbs and shorter hindlimbs (Martin and Johnson, 1995) so that the limbs are of similar proportions (Grzimek, 1990).
The largest of Australia's arboreal mammals (Martin, 1995), Dendrolagus bennettianus exhibits sexual dimorphism in size, with males weighing 11.5-13.7 kg, and females weighing 8-10.6 kg. The non-prehensile tail (730-800 mm females, 820-840 mm males) is longer than head and body length (690-705 mm females, 720-750 mm males), of uniform width (Martin and Johnson, 1995), and used as a counterbalance (Grzimek, 1990).
With mostly dark brown pelage, the chin, throat, and belly are lighter in D. bennettianus. It also has black feet, a greyish forehead, and rusty tint to its snout, shoulders, neck, and back of the head. The tail is marked at the base with a black patch, and dorsally with a light patch. (Martin and Johnson, 1995).
Range mass: 8 to 14 kg.
Average mass: 10.5 kg.
Habitat and Ecology
Within their range, Dendrolagus bennettianus inhabit highland rainforest down to lowland riparian forests (Newell, 1999). They are usually found in the canopy, but will locomote terrestrially to travel within their territory or consume leaves and fruit that have fallen to the ground (Martin and Johnson, 1995).
Terrestrial Biomes: rainforest
Dendrolagus bennettianus exhibits mostly folivory, particularly favoring trees such as Ganophyllum, Aidia, and Schefflera, the vine Pisonia, and the fern Platycerium (Martin and Johnson, 1995). Fruit is also taken, when available (Martin and Johnson, 1995), both arboreally and terrestrially (Grzimek, 1990). Food trees are defended within territories, where preferred ones are visited regularly (Martin, 1995).
Life History and Behavior
Lifespan, longevity, and ageing
Whereas certain species of tree-kangaroo, such as Dendrolagus matschiei, have been successfully bred and studied in captivity, most are little studied so that reproductive behavior and processes are poorly understood.
Females breed annually (Martin and Johnson, 1995), producing one young per litter (Grzimek, 1990). Young accompany their mothers for up to two years (Martin and Johnson, 1995), of which the first nine months is spent in the pouch. Females may exhibit embryonic diapause or quiescence (Martin and Johnson, 1995), in which case quiescence is most likely lactational, as with other macropods. Living in tropical rainforest with little differentiation between seasons, Dendrolagus are not likely to be seasonal breeders, and, instead, are probably opportunistic breeders (Tyndale-Biscoe and Renfree, 1987).
Joeys typically remain with their mothers until developing into sub-adults, usually weighing over 5 kg. Adult males usually only contact juveniles when consorting with adult females, although males accompanying juveniles have been observed after the loss of the mother (Martin, 1995). Mating appears to be polygynous, with the territories of several females encompassed by that of a single male (Martin and Johnson, 1995).
Captive tree-kangaroos (e.g. D. matschiei and D. goodfellowi) have lived and remained reproductively capable for over 20 years, though this is probably more than exhibited in the wild. It is estimated that Dendrolagus may ideally produce 6 offspring in a lifetime. (Newell, 1999)
Average number of offspring: 1.
IUCN Red List Assessment
Red List Category
Red List Criteria
(Wilson and Reeder, 1993)
Though quite rare and probably with relatively small total population numbers, virtually all Dendrolagus bennettianus inhabit protected areas. Their most dangerous potential threat, hunting by humans, is quite limited, and poses no immediate risk of hampering survival of this species. Dendrolagus bennettianus actually appears to be expanding its utilized habitats within its range, with the modern decline in aboriginal hunting, dispersing from montane highlands to lower elevation forest habitats (Newell, 1999). Previously, hunting drove them to the mountains, where taboos apparantly prevented further pursuit by humans (Martin, 1995) (Martin and Johnson, 1995).
Areas of deforestation and habitat interruption by roads, however, undoubtedly have a negative impact on Dendrolagus populations, however. Though deforestation does not seem to have direct, immediate impact on populations, the resulting fragmentation of habitats leaves Dendrolagus more susceptible to terrestrial predation. Intended "safe" passageways to allow animals to avoid roads do not seem to work well for tree-kangaroos, due to preferred routes within territories and their large body size relative to other local arboreal mammals. (Newell, 1999)
CITES: appendix ii
IUCN Red List of Threatened Species: near threatened
In the past it was threatened by hunting pressure by Aborigines (Martin and Johnson 2008). Resumption of hunting might constitute a future threat (Maxwell et al. 1996).
Relevance to Humans and Ecosystems
Economic Importance for Humans: Negative
Bennett's tree-kangaroos, being rare and extremely elusive, seldom come in contact with humans, the main factor that makes them difficult to study (Martin and Johnson, 1995). Their range is largely encompassed by the limits set by the Wet Tropics World Heritage Area (WTWHA), and so their foraging does not extend into human-inhabited areas to cause agricultural or other problems for humans (Newell, 1999).
Economic Importance for Humans: Positive
Though mostly inhabiting protected areas delineated by the Wet Tropics World Heritage Area, Dendrolagus bennettianus is susceptible to hunting from aboriginal tribes in the area. Hunting, including that of tree-kangaroos, is important to some local tribes both for sustenance and for cultural reasons (Newell, 1999).
Bennett's tree-kangaroo (Dendrolagus bennettianus) is a large tree-kangaroo. Males can weigh from 11.5 kg up to almost 14 kg (25 to 31 lbs), while the females range between about 8 to 10.6 kg (17.6 to 23 lbs). They are very agile and are able to leap 9 metres (30 ft) down to another branch and have been known to drop as far as 18 metres (59 ft) to the ground without injury.
Habitat[edit source | edit]
This very elusive (or "cryptic") tree-kangaroo is found in both mountain and lowland tropical rain forests south of Cooktown Queensland to just north of the Daintree River; an area of only about 70 km by 50 km (44 miles by 31 miles). It is also occasionally found in sclerophyll woodlands. It lives almost completely on the leaves of a wide range rainforest trees, notably Schefflera actinophylla (the Umbrella Tree), vines, ferns and various wild fruits.
Diet[edit source | edit]
The Bennett's tree-kangaroo is a herbivore.It mostly eats leaves off 33 different plant species.
Physical description[edit source | edit]
Like other tree-kangaroos it has longer forelimbs and shorter hindlimbs than terrestrial kangaroos and a long bushy tail. It is mostly dark brown above and lighter fawn on chin, throat and lower abdomen. The forehead and muzzle are greyish. The feet and hands are black. The tail has a black patch at the base and a light patch on the upper part. The ears are short and rounded
Conservation status[edit source | edit]
Although the IUCN still rates the status of Bennett's tree-kangaroo as "near threatened", its numbers seem to be increasing and its range expanding. Sightings have become far more common in recent years. In 2006 a dead specimen was found along Amos Bay Road, just south of Cooktown. The increases in numbers and range are likely because most of its range is now protected under World Heritage legislation, and it is no longer hunted by Aboriginal people. Both Roger Martin and Lewis Roberts, two of the world's top experts on this species, agree that it should now be classified as "secure."
Footnotes[edit source | edit]
- Groves, C. P. (2005). Wilson, D. E.; Reeder, D. M, eds. Mammal Species of the World (3rd ed.). Baltimore: Johns Hopkins University Press. p. 59. OCLC 62265494. ISBN 0-801-88221-4.
- Winter, J., Burnett, S. & Martin, R. (2008). Dendrolagus bennettianus. In: IUCN 2008. IUCN Red List of Threatened Species. Retrieved 28 December 2008. Database entry includes justification for why this species is listed as near threatened
- Cronin (2000).
- Martin (2005).
- Martin et al (1996), pp. 94–95.
- Nguyen, H. (2000). "Dendrolagus bennettianus". Animal Diversity Web. Retrieved 2006-11-25.
- Martin (2005).
References[edit source | edit]
|Wikispecies has information related to: Bennett's tree-kangaroo|
|Wikimedia Commons has media related to: Dendrolagus bennettianus|
- Cronin, Leonard (2000). Australian Mammals: Key Guide (Revised Edition). Envirobooks. Annandale, Sydney, Australia. ISBN 0-85881-172-3.
- Martin, Roger, et al. (1996). Tree Kangaroos: A Curious Natural History. Reed Books, Port Melbourne, Vic., Australia. ISBN 0-7301-0492-3.
- Martin, Roger (2005). Tree-kangaroos of Australia and New Guinea. CSIRO Publishing, Collingwood, Vic., Australia. ISBN 0-643-09072-X.