In forwarding the adult skin, Captain Zimmer wrote 'I have just come back from a trip through entirely unknown and uninhabited country ... through which we had to cut our way on a compass course. One of my police shot what I take to be a tree-climbing kangaroo ...'

-- Australian Museum Curator Ellis Le Geyt Troughton and A.S. Le Souef, quoting the collector Captain Zimmer in their description of Dendrolagus Spadix, 1936.

THIS RATHER DRAB species is the only member of the short-footed group of tree-kangaroos that is restricted to the lowlands. Although it may appear to be rather different externally, it is closely related to Goodfellow's Tree-kangaroo (Dendrolagus goodfellowi). Indeed, it was once thought to be no more than a variant of this species.

Its distribution is centered on the exceptionally rugged limestone karst of the Papuan Plateau in the south-central part of New Guinea, but it extends right down to sea-level in uninhabited swamp forest southeast of Lake Murray on the Fly River. It also extends close to the coast in Gulf Province.

Its uniform chestnut coat is short and thin, particularly on the underside. The belly is slightly paler than the back, but apart from this the only variation in colour comes from an occasional, often incomplete, ring of yellow fur around the tail, and occasionally two faint, short, yellow stripes on the rump. Only two individuals (both adult males) have ever been weighed; these were 7 and 9.1 kilograms in weight. juveniles differ from adults in their denser fur and yellowish belly.

Almost nothing is known of the biology of this unusual animal. It does appear, however, to be extremely vulnerable to human hunting pressure. As a result, its distribution hardly overlaps at all with that of people. Interestingly, the inhabitants of the Lake Marray area believe that a vast region lying southeast of the lake is uninhabited as a result of the tree-kangaroos, which in the distant past drove people from the region. They portray the Lowland Tree-kangaroo as a dangerous creature, which hunts in much the same way as they do. These meagre and unsatisfying notes must remain the sum total of our knowledge of this species until further fieldwork is undertaken.