(AILUROPS URSINUS & STIGOCUSCUS CELEBENSIS). One of the most curious and engaging creatures of the lowland forest is the cuscus. Cuscus are marsupials, or pouched mammals. Like their relative the kangaroo, they give birth to tiny, partially developed infants than spend their first month of life nursing in the mother's fur-lined pouch. As the young mature, they may be seen traveling on their mother's back, tails intertwined. These round-faced mammals with their small ears and densely furred bodies are the slow-motion acrobats of the forest. A prehensile tail, tough and leathery for the lower half of its length, is used like a fifth appendage. When crossing between trees the tail coils around a branch like an anchor while their front limbs secure a hold. Back limbs dangle free at first, then slowly swing forward to grasp a sturdy branch. Sulawesi defines the western most range of cuscus distribution; no cuscus are found across Wallace's line. Two species occur in Sulawesi: The Bear cuscus, Ailurops ursinus, the largest and most primitive of all cuscus, Stigocuscus celebensis, which curiously represents the smallest and possibly most advenced cuscus species. These cuscus probably derived from ancestors that rafted across the Banda Sea from New Guinea before the end of the last Ice Age some 11,000 years ago. The Bear cuscus, with a head to tail length of more than a meter, is the larges mammal of Sulawesi's upper canopy, with the exception of the Crested black macaque. This dark-brown herbivore is found mainly in pairs, feeding on new shoots and leaves of a few favored trees such as Garuga floribunda, Koodersiodendron pinnatum, or the introduced Melia azedarach. Because many plants protect their leaves from herbivores with defensive componds like tannins and phenolics, bear cuscus must be selective in their diet, choosing species and ages of leaves that are low in these compounds. Bear cuscus spend nearly 65% of their day resting and probably digesting leaves. Although reported to be diurnal, they are also active at night. Anecdotal accounts suggest that cuscus interactions can be aggressive, accompanied by a series of sharp clicks and hisses. The dwarf cuscus differs from its larger relative by being nocturnal and primarily frugivorous. Virtually nothing is known about its biology or behavior. Like the mountain cuscuses of Papua New Guinea, the Dwarf cuscus is believed to spend its day secure in tree cavities. |
