New Arrivals: Ground Cuscus

Ground Cuscus

Recently gone on show in Twilight World is one of the few species of marsupial (other than kangaroos and wallabies) to be seen in zoos outside Australia – a pair of Ground Cuscus Phalanger gymnotis. Closely related to the Brushtail Possum Trichosurus arnhemensis which is widely spread throughout Australia, and as an introduced species is a major threat to New Zealand’s native fauna, the Ground Cuscus is currently listed as Least Concern, although deforestation and over-hunting may be a cause of local declines. It is quite a widespread species however, so as a species it is not in any especial trouble.

The same cannot however be said for some of its relatives. Several species of Phalanger are widespread and share the Ground Cuscus’ status, but several species are confine to islands or seem to be geographically isolated, and these are in far more trouble. The Telefomin Cuscus P.matanamin is only known from six individuals and the only site where it was known to occur was completely destroyed by fire in 1998, and it is either already extinct or Critically Endangered. The Woodlark Cuscus P.lullulae is only known from a few islands off Papua New Guinea, and the main population on Woodlark Island is threatened by Malaysian palm oil plantation development

Bear Cuscus

The Phalanger family Phalangeridae is one of the few groups of Australian mammals to successfully cross Wallaces Line that separates Australasian animals from those of mainland Asia. The Bear Cuscus Ailurops (2 species) is known from Sulawesi and nearby islands, and very little is known about it. Even less known are its smaller relatives the Dwarf cuscuses Strigocuscus (also 2 species), which occur on the same islands, although not necessarily in the same habitat. With a range from Sulawesi through New Guinea into northern Australia, the Common Spotted Cuscus Spilocuscus maculatus has a similar status to the Ground Cuscus, and like it has several close relatives with restricted ranges that are in a more serious state.

Common Spotted Cuscus

All the Phalangerids seem to have a fairly similar diet, being basically generalists feeding on flowers, fruits, nectar and a varying amount of animal food. Most are about the size of a domestic cat, and tend to live mainly in trees – the Ground Cuscus is unusual in using terrestrial burrows, although even it spends a lot of time in trees. In some ways cuscuses can be thought of as the ecological equivalents of primates, although unlike them (which are of course placental mammals) they are solitary and nocturnal by nature and are not renowned for their intelligence.

As a fairly unspecialised marsupial, the Ground Cuscus has a pouch where it retains its single baby for around 3 months, after which it takes another 2 – 4 months to become independent, at which point it leaves to join the adult population. They breed all year round, and the actual pregnancy only takes 13 days. Lifespan in the wild is unclear, but in captivity they can live to be 15 years old.

(images from wikipedia)