Tree-kangaroo

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Tree-kangaroo[1]
Matschie's tree-kangaroo (Dendrolagus matschiei)
Conservation status
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Infraclass: Marsupialia
Order: Diprotodontia
Family: Macropodidae
Subfamily: Macropodinae
Genus: Dendrolagus
Müller, 1840
Type species
Dendrolagus ursinus
Müller, 1840
Species

about 12; see text.

The tree-kangaroo is a marsupial from the family Macropodidae (macropods, meaning 'large foot') adapted for arboreal locomotion. They inhabit the tropical rainforests of New Guinea, far northeastern Queensland and some of the islands in the region. Most tree-kangaroos are considered threatened due to hunting and habitat destruction. The tree-kangaroo is the only true arboreal member of the kangaroo family.[2]

Taxonomy[edit]

The Seri's tree-kangaroo (D. stellarum) has been described as a subspecies of the Doria's tree-kangaroo (D. dorianus),[3][4] however, some recent authorities have treated it as a separate species based on its absolute diagnostability.[1] It has further been suggested that the D. mayri taxon may represent a valid species,[5] but as it is known only from a single preserved specimen, most authorities have retained it as a subspecies of D. dorianus.[1] The case for the golden-mantled tree-kangaroo (D. pulcherrimus) is comparable to that of D. stellarum; it was initially described as a subspecies of D. goodfellowi,[3] however, recent authorities have elevated it to species status based on its absolute diagnostability.[1] A population of the Tenkile (Scott's tree-kangaroo) recently discovered from the Bewani Mountains may represent an undescribed subspecies.[6]

Description[edit]

Compared with terrestrial kangaroos, tree-kangaroos have several adaptations to an arboreal life-style. Tree-kangaroos have shorter and broader hind feet with longer, curved nails. They also have a sponge-like grip on their paws and soles of their feet. Tree-kangaroos have a much larger and pendulous tail than ground-dwelling kangaroos, giving the tree-kangaroo enhanced balance while moving about the trees. Tree-kangaroos, like terrestrial kangaroos, do not sweat; to cool their bodies, they lick their forearms and allow the moisture to evaporate.[7]

Lumholtz's tree-kangaroo[edit]

The Lumholtz's tree-kangaroo (Dendrolagus lumholtzi) is noctural making it difficult to study regardless of their diminishing population.[2] The male weighs about 15.6 lbs and measures 23.3 inches long (head to the base of the tail) with an average tail length of 27.4 inches. The female weighs about 13.2 lbs and measures 21.8 inches long (head to the base of the tail)with an average tail length of about 27.5 inches. The tail on both the male and female of this species is the same size, if not longer than the body, indicating the importance of the tail which is primarily used for balance.[8]

Distribution and habitat[edit]

Tree-kangaroos inhabit the tropical rainforests of New Guinea, far northeastern Queensland and some of the islands in the region — in particular the Schouten Islands and the Raja Ampat Islands near the northwestern coast of New Guinea.[9] Although most are found in mountainous areas, several species also occur in lowlands, such as the aptly named lowlands tree-kangaroo. Most tree-kangaroos are considered threatened due to hunting and habitat destruction. Because most of their motion and living involves climbing and jumping from tree to tree, they developed better locomotion. Tree-kangaroos thrive in tree tops as opposed to their cousin the kangaroo which survives on mainland in Australia. Two species of kangaroo are found in Australia, Bennett's (Dendrolagus bennetianus) which is found north of the Daintree River and Lumholtz's (Dendrolagus lumholtzi). Tree-kangaroos have adapted better to regions of high altitudes.[10] Tree-kangaroos have at least fifteen known subspecies living in Papua New Guinea and Australia. Tree-kangaroos must find places comfortable and well adapted for breeding as they only give birth to one joey per year. They are known to have one of the most relaxed and leisurely birthing seasons. They breed cautiously in treetops during monsoon season. Their habitats are breeding grounds for danger as they can easily fall prey to their natural predator, amethystine pythons, which also climbs and lives amongst the treetops in the forests. Tree-kangaroos are known to be able to live in both mountainous regions and low-land locations.[11]

Evolution[edit]

DNA and fossil records show that the tree-kangaroo split away from the rock-wallabies between 5 and 7 million years ago. The fossil records also show that when plate tectonics shifted north, the Australian plates brought New Guinea and Northern Australia into the Tropic Zone providing an environment for tree-kangaroos with no competition.[12]

The evolutionary history of tree-kangaroos begins with a rainforest floor dwelling pademelon-like ancestor (Thylogale spp.).[13] This ancestor evolved from an arboreal possum-like ancestor as is suspected of all macropodid marsupials in Australia and New Guinea. During the late Eocene the Australian/New Guinean continent began a period of drying that caused a retreat in the area of rainforest.[14] The retreat of the rainforest forced the ancestral pademelons to begin living in a dryer, rockier environment. After some generations of adaptation to the new environment, the pademelons evolved into rock-wallabies (Petrogale spp.).[13] The rock-wallabies developed a generalist feeding strategy due to their dependence on a diverse assortment of vegetation refuges.[15] This generalist strategy allowed the rock-wallabies to easily adapt to malesian rainforest types that were introduced to Australia from Asia during the mid-Miocene.[13][14] The rock-wallabies that migrated into these introduced forests adapted to spend more time climbing trees. One species in particular, the proserpine rock-wallaby (Petrogale persephone), displays equal preference for climbing trees as for living in rocky outcrops.[13] During the late-Miocene the semi-arboreal rock-wallabies evolved into the now extinct tree-kangaroo genus Bohra.[16] Global cooling during the Pleistocene caused continent wide drying and rainforest retractions in Australia and New Guinea.[17] The rainforest contractions isolated populations of Bohra which resulted in the evolution of today's tree-kangaroos (Dendrolagus spp.) as they adapted to lifestyles in geographically small and diverse rainforest fragments, and became further specialized for a canopy dwelling lifestyle.[18]

Locomotion[edit]

Tree-kangaroos are slow and clumsy on the ground. They move at about walking pace and hop awkwardly, leaning their body far forward to balance the heavy tail. But in trees they are bold and agile. They climb by wrapping the forelimbs around the back of a tree and hopping with the powerful hind legs, allowing the forelimbs to slide. They are expert leapers; 9 metres (30 ft) downward jumps from one tree to another have been recorded, and they have the extraordinary ability to jump to the ground from 18 metres (59 ft) or more without being hurt![citation needed]

Eating habits[edit]

Tree-kangaroos' main diet are leaves and fruit that it can find up in the tree; from time to time they will also scavenge on the ground for them. Other components of the tree-kangaroos' eating habits are grains, flour, eggs, sap, young birds, and tree bark.[7]

Threats[edit]

The two most relevant threats to all species of tree-kangaroos are habitat loss and hunting. Tree-kangaroo habitats are being replaced by logging and timber production; along with coffee, rice and wheat production. This habitat loss can make the tree-kangaroos more open to predators, like domestic dogs. Being hunted by native tribles and communities also steeply contribute to the tree-kangaroos' population decline.[7] Research has been conducted on the Lumholtz's tree-kangaroo, a species that dwells in the rain forests of southern Australia to determine the average cause of death. This research showed that out of every 27 deceased tree-kangaroos 11 of them had been killed by vehicles, 6 were killed by dogs, 4 by parasites and the other 6 from other causes.[19]

Reproduction[edit]

A female tree-kangaroo's fertile period is estimated to be about two months long. Tree-kangaroos in their reproductive mode are a bit extreme compared to most marsupials. They have one of the longest marsupial offspring development/maturation periods and if compared to other marsupials similar in size they have the longest. Not much is known about the reproduction of the tree-kangaroo in the wild, the only published data is from those that were in captivity.[20] However, observed in these captivity studies was that pouch life for the young is 246–275 days long and weaning occurred 87–240 days later. Female tree-kangaroos reach sexual maturity as early as 2.04 years and males at 4.6 years.[21]

Gallery[edit]

See also[edit]

References[edit]

  1. ^ a b c d Groves, C. P. (2005). Wilson, D. E.; Reeder, D. M, eds. Mammal Species of the World (3rd ed.). Baltimore: Johns Hopkins University Press. pp. 59–61. OCLC 62265494. ISBN 0-801-88221-4. 
  2. ^ a b Procter-Gray, Elizabeth; Udo Gansiosser (May 1987). "The Individual Behaviors of Lumholtz's Tree-Kangaroo: Repertoire and Taxanomic Implications". Journal of Mammalogy 67 (2): 343–352. Retrieved 25 October 2013. 
  3. ^ a b Flannery, T. (1995). Mammals of New Guinea. Reed Books. ISBN 0-7301-0411-7. 
  4. ^ Nowak, R., ed. (1999). Walker's Mammals of the World (6th ed.). Johns Hopkins University Press. ISBN 0-8018-5789-9. 
  5. ^ Wondiwoi Tree Kangaroo Tenkile Conservation Alliance
  6. ^ Tenkile Tree Kangaroo Tenkile Conservation Alliance
  7. ^ a b c "WWF - Tree Kangaroo". Wwf.panda.org. Retrieved 2013-11-13. 
  8. ^ Kazmeier, Lars. "Tree-Kangaroo Info". Tree-Kangaroo and Mammal Group Inc. Retrieved 25 October 2013. 
  9. ^ USA (2013-10-23). "Matschie's Tree Kangaroos, Matschie's Tree Kangaroo Pictures, Matschie's Tree Kangaroo Facts - National Geographic". Animals.nationalgeographic.com. Retrieved 2013-11-13. 
  10. ^ Sullivan, Rachel (2007-12-13). "Treetop kangaroos " Nature Features (ABC Science)". Abc.net.au. Retrieved 2013-11-13. 
  11. ^ "Tree Kangaroo - Animal Facts and Information.". Bioexpedition.com. Retrieved 2013-11-13. 
  12. ^ Janice, Christine (1/03/2013). "Fossil Focus: The evolution of tree kangaroos". Palaentology Online. 3 3: 1–6. 
  13. ^ a b c d Martin, Roger William (July 2005). Tree-kangaroos of Australia and New Guinea. CSIRO. ISBN 978-0-643-09072-9. 
  14. ^ a b Archer, Mike (1991). Riversleigh: The Story of Animals in Ancient Rainforest of Inland Australia. Bangowlah, NSW: Reed Books. 
  15. ^ Tuft, KD; Crowther, M.S.; McArthur, C. (2011). "Multiple scales of diet selection of brush-tailed rock-wallabies (Petrogale penicillata)". Australian Mammalogy 33: 169–180. doi:10.1071/am10041. 
  16. ^ Flannery, Timothy; Martin, Roger; Szalay, Alexandra (1996). Tree-kangaroos: A Curious Natural History. Melbourne VIC: Reed Books. pp. 68–72. ISBN 978-0-7301-0492-6. 
  17. ^ Hopkins, M. S.; J. Ash, A. W. Graham, J. Head, and R. K. Hewitt (1993). "Charcoal evidence of the spatial extent of the Eucalyptus woodland expansions and rainforest contractions in North Queensland during the late Pleistocene". Journal of Biogeography 20: 357–372. doi:10.2307/2845585. 
  18. ^ Prideaux, G. J., Warburton, N.M. (2010). Macropods:. Collingwood, VIC: CSIRO. pp. 137–151. 
  19. ^ John Chambers. "! Lumholtz Tree-kangaroo ! Tropical Rainforest, Far North Queensland Australia". Rainforest-australia.com. Retrieved 2013-11-13. 
  20. ^ "Tree-Kangaroo and Mammal Group - helping to conserve North Queensland's rich mammal fauna - TREE KANGAROO INFO". Tree-kangaroo.net. Retrieved 2013-11-13. 
  21. ^ http://www.publish.csiro.au/?act=view_file&file_id=WR02090.pdf

External links[edit]