It was such a thrill seeing the twins for the first time. We were looking into the enclosure when two tiny heads emerged from the pouch. We froze, unable to reach for our cameras for fear of disturbing them ...

-- Valerie Thompson of San Diego Zoo, describing seeing twin Tree-kangaroo joeys for the first time, December 1994.

TIMBOYOK IS THE only subspecies of Goodfellow's Tree-kangaroo (Dendrolagus goodfellowi) to have been held in captivity in zoos. It has proven to be relatively easy to keep, and a number of zoological parks presently display it.

It is a small tree-kangaroo, averaging 7.5 kilograms in weight, with no difference in size between the sexes. It has a striking appearance. The eyes are often blue, and the coat is warm chestnut with distinct double golden stripes of variable size and intensity over the neck and rump. The golden forearms are sharply set off from the brown upper arms. The skin of the hands and feet is flesh-coloured, the claws light brown. Each individual has a unique pattern of yellow rings and blotches on the tail. This makes individuals recognisable at a distance, a characteristic that may be important in maintaining the social structure of the species.

There is some indication that it forms pairs, an unusual reproductive strategy among marsupials. It has a long gestation period (44.5 days). The young stay in the pouch for eight to ten months and, as with Matschie's Tree-kangaroo (Dendrolagus matschiei), accompany the mother for only two to three months after. This is a remarkably brief period of association between a mother tree- kangaroo and her 'Joey at heel'.

A single instance of twins has been recorded, but one young had to be removed to be hand-reared when it fell from the pouch several times. Timboyok is a long-lived species, with some captive individuals surviving into their late teens.

It appears to be most active in the early morning and late afternoon, although where it is heavily hunted it may become nocturnal. Casual observations in captivity suggest to me that it is more highly strung and flighty than Doria's Tree-kangaroo (Dendrolagus dorianus dorianus). Details of its diet in the wild are uncertain, but it may take some fruit as well as leaves.

As with Ifola (Dendrolagus dorianus notatus), its distribution is centred on Papua New Guinea's densely populated central highlands. It extends a little further to the west, however, being found in the sparsely populated Hunstein Mountains and Thurnwald Range. Nonetheless, its conservation status must be regarded.as perilous, for it is largely restricted to mid-elevation oak forest, which is where human disturbance is greatest.

Mianmin hunters living at the base of Mount Bubiari in far western Papua New Guinea have told me that it still inhabits their area, but it is clearly rare. The only specimen I collected was an old skull that had apparently been retrieved from the remains of a fallen house. Nevertheless, the Mianmin regarded the animal fondly. They tell, somewhat wistfully, of how Timboyoh lives on the mountain summit, far above them. There it suns itself, while its young one plays nearby in the branches. From its high perch, it often looks down to observe the difficult life of men who toil on the river flats below.