Biology Reference
In-Depth Information
these islands, some of the endemic plants might be superabundant locally, not rare in number
at all, though still rare by the criterion of range. Others are rare not only in range but also in
number.
Other members of the expedition were concentrating on vertebrates other than birds. One
evening the Kwerba guides reported a brief sighting of a golden-mantled tree kangaroo, one
of the rarest mammals in New Guinea and one of the most uncommon in this group of mar-
supials.
The golden-mantled is a handsome six kilograms of silky chestnut-brown fur offset by
light underparts and a yellow wash on the neck, cheeks, and feet. A double golden racing
stripe runs down the back. The yellow and maroon furry tail is almost one meter long. The
naturalists' find was the first sighting of this animal in the Indonesian portion of New Guinea
and represented only the second known site of occurrence. Tim Flannery, a world authority
on New Guinea mammals, first described this species in 1993; it had been sighted across the
national border to the east, in Papua New Guinea.
We don't usually think of kangaroos hanging out in trees, but ten of New Guinea's native
kangaroo species prefer an arboreal life. Tree kangaroos will never match the acrobatics of
monkeys or gibbons, but tree roos are nevertheless skilled leapers and skydivers, able to fall
twenty meters to the ground without breaking a limb. Once on terra firma, tree roos lack
the athletic grace of a wallaby or wallaroo, but they can still scamper at speed. The arboreal
lifestyle, however, is a comparatively recent evolutionary move. Not unlike whales, whose
ancestors were land mammals that headed back to sea, tree kangaroos evolved from ground-
dwelling kangaroos that in turn descended from arboreal opossums.
