Tree-kangaroo

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{{Taxobox | color = pink | name = Tree-kangaroos | image = PHOTO_2006-01-03_143248_resize_resize.JPG | image_caption = Buergers' Tree-kangaroo, Dendrolagus goodfellowi buergersi | regnum = Animalia | phylum = Chordata | classis = Mammalia | subclassis = Marsupilia | ordo = Diprotodontia | familia = Macropodidae | subfamilia = Macropodinae | genus = Dendrolagus | genus_authority = Müller, 1840 | type_species = Dendrolagus ursinus | type_species_authority = Müller, 1840 | subdivision_ranks = Species | subdivision = About 12; see text. }} Tree-kangaroos are macropods adapted for life on trees. They are found in the rainforests of New Guinea, far north-eastern Queensland, and nearby islands, usually in mountainous areas.

It is understood that tree kangaroos evolved from creatures similar to modern kangaroos and wallabies, as they retain many standard macropod adaptations to life in the plains—notably the massive hind legs and long, narrow feet which allow orthodox macropods to travel fast and economically on the ground. Tree kangaroos have developed exceptionally long tails for balance, and stronger forelimbs for climbing. The feet are shorter and wider, they have longer claws on all feet, and rubbery soles for better grip.

The ancestors of all kangaroos are believed to have been small arboreal marsupials that looked like some of Australia's present-day possums. The earliest macropods diverged from this line when they descended to the ground and evolved bodies adapted for rapid motion over the earth and rocks. Why ancestors of the tree kangaroos at some point returned to the trees is not known.

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 trunk of a tree and hopping with the powerful hind legs, allowing the forelimbs to slide. They are expert leapers: 9-metre downward jumps from one tree to another have been recorded, and they have an extraordinary ability to jump to the ground from height without ill effect: 18 metres or more.

Image:Kanga2031.jpg

They feed mostly on leaves and fruit, taken both in trees and on the ground. Other morsels are accepted when available, including grain, flowers, sap, bark, eggs and young birds. Their teeth are adapted for tearing leaves rather than cutting grass. They have large stomachs that function as fermentation vats, similar to the stomachs of cows and other ruminant herbivores, where bacteria break down fibrous leaves and grasses.

Image:Tree kangaroo at melbourne zoo.jpg

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Species

Grizzled Tree-kangaroo, Dendrolagus inustus, northern and western New Guinea, plus Japen and Waigeo islands
Lumholtz's Tree-kangaroo, Dendrolagus lumholtzi, Queensland
Bennett's Tree-kangaroo, Dendrolagus bennettianus, Queensland
Ursine Tree-kangaroo, Dendrolagus ursinus, western New Guinea
Matschie's Tree-kangaroo, Dendrolagus matschiei, eastern New Guinea
Doria's Tree-kangaroo, Dendrolagus dorianus, far western, central, and southeastern New Guinea
Goodfellow’s Tree-kangaroo, Dendrolagus goodfellowi, central New Guinea
- Buergers' Tree-kangaroo, Dendrolagus goodfellowi buergersi
Golden-mantled Tree-kangaroo, Dendrolagus pulcherrimus, Foja mountains, western New Guinea
Lowlands Tree-kangaroo, Dendrolagus spadix, lowlands New Guinea
Seri's Tree-kangaroo, Dendrolagus stellarum
Dingiso, Dendrolagus mbaiso, western New Guinea
Tenkile, Dendrolagus scottae, northern New Guinea

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References

Flannery, Timothy Fridtjof, et al. 1996. Tree Kangaroos: A Curious Natural History. Reed Books, Melbourne. ISBN 0-7301-0492-3
Scientists hail discovery of hundreds of new species in remote New Guinea, The Independent, 7th February 2006 [1]
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