Indonesian Cuscuses (Diprotodontia: Phalangeridae): Status and Perspective

Within the gliding mammals has evolved in Three orders, i.e Rodentia, Dermoptera, and Marsupialia. The marsupials include a number of gliding genera believed that the gliding habit evolved independently. Marsupial consist of seven orders, Diprotodontia is the largest and most ecologically diverse. More than 125 living diprotodontian species are currently recognized. Most diprotodontians are herbivorous, but there are also forms specialized for nectarivory, folivory, and insect-omnivory. The family Phalangeridae comprises approximately ± 24 extinct and extant species, including brushtailed possums (Trichosurus), scaly tailed possum (Wyulda) and cuscuses (Phalanger, Strigocuscus, Spilocuscus and Ailurops) (Raterman et al., 2006). Trichosurus and Wyulda are found predominately in Australia whereas Phalanger and Spilocuscus are, for the most part, limited to Maluku, Papua, New Guinea, Timor island and surrounding islands (Flannery, 1994; Kunda et al., 2016; 2017; Widayanti et al., 2015;  2020). Extant species of Strigocuscus are found in Sulawesi and surrounding islands (Flannery 1994). Ailurops contains a single species, A. ursinus, the bear cuscus (Flannery et al. 1987), found on Sulawesi and nearby islands. Two taxa whose phylogenetic placements are key for understanding evolutionary relationships are Ailurops ursinus and Strigocuscus celebensis.

Phalangeridae is one family has generated the most phylogenetic and taxonomic uncertainties of any family within Order Diprotodontia, whether based on morphological or biochemical data (Kirsch and Wolman, 2001; Ruedas and Morales, 2005). The various phylogenetic relationships for this family have led to different biogeographic models in regard to the site of origin (Australia or Sulawesi) and directions of dispersal (Australia to the Sulawesi or from the Sulawesi to Australia, and spred to surrounding islands), for taxa within the family (Ruedas and Morales, 2005). Case et al (2008) stated that oligocene deposits in South Australia from the Etadunna and Wipajiri formations in the Lake Eyre Basin, and from the Namba Formation in the Frome Basin, have produced a wide range and the earliest records of most of possum families extinct at the time and extant until now. Archer (1987), reported that had been no positive sign that Phalangeridae was recovered from deposits of the Etadunna Formation. In addition Springer et al. (1990; 1997) stated that the absence of Phalangeridae in the late oligocene had been confusing considering that the earlier molecular studies  which produced divergence time data from molecular sequences, indicated that thePhalangeridae lineage should be present by the Eocene.

Cuscus is one of the endemic species of marsupialia of Eastern Indonesia whose distribution includes Papua, Maluku, Sulawesi and Timor, which is classified as the family of Phalangeridae.

In Indonesia there are 4 genus of cuscus, namely Phalanger, Spilocuscus, Ailurops and Strigocuscus. The cuscus has a different coat color pattern based on its genus. The genus Spilocuscus consists of 3 species and the genus Phalanger consists of 8 species. Outside Indonesia, the distribution of cuscus includes Papua New Guinea and parts of Australia.

Cuscus is one of the animals that has a distinctive morphological character with a limited distribution area, limited reproduction and a serious threat due to habitat degradation and hunting, so that it has been protected by the Indonesian government under Law No. and 5 of 1990 (concerning Conservation of Living Natural Resources and their Ecosystems) and Government Regulation No. 7 of 1999 (concerning the Preservation of Plant and Animal Species) as amended by the Regulation of the Minister of Environment and Forestry Number P.106 / MENLHK / SETJEN / KUM.1 / 12/2018 concerning the Second Amendment to the Regulation of the Minister of Environment and Forestry Number P. 20 / MENLHK / SETJEN / KUM.1 / 6/2018 concerning Types of Protected Plants and Animals. Globally, cuscuses are categorized as threatened under the IUCN and the Appendix II Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). These protection considerations are of course based on species endemicity and population dynamics in the wild as well as hunting threats and habitat degradation.

Indonesia with a plain area of only about 1.3% of the earth's surface is rich in various types of wildlife species and various types of ecosystems, most of which are not found in any hemisphere. In addition, Indonesia has about 27,500 plant species (10% of the world's flowering plants), 515 mammal species (12% of the world's mammals), 1,539 bird species (17% of all bird species in the world), 25% of all fish species in the world. North Sulawesi has many species of very high diversity, and approximately 70% of the 114 animal species known to exist are rare and endemic species including bear cuscus (Aillurops ursinus) (MacKinnon, 1986).

The natural resources owned by the Indonesian people are the basic capital of a very strategic national development, an ecological comparative advantage that is not owned and cannot be developed by other nations and countries. Seeing the importance of nature conservation, the Indonesian government is absolutely committed to protecting 10% of the plains area and 20 million ha of coastal and marine habitats as conservation areas. Cuscus is a marsupial animal / animal (classified as marsupials). Based on several sources, the spread of cuscus is almost all over eastern Indonesia. According to animal experts, this animal is described as having a rather large and sturdy body and also having a body length the size of a two-month-old pig. The genus that includes cuscus species are Aillurops, Phalanger, Spilocuscus and Strigocuscus. Their coat coloring pattern is also distinguished into two genera, namely the genus Spilocuscus and Phalanger, each consisting of 3 to 8 species, while on the island of Sulawesi there are three endemic species of cuscus, namely Aillurops ursinus, Phalanger pelengensis and Strigocuscus celebensis.

Forest is a habitat or place to live for the life of various flora and fauna, including humans. Forests are the life support for every creature on earth. Forests for wildlife are very important for their survival, especially for breeding, playing places, looking for food, interacting with other wildlife. Thus, wild animals are very dependent on the existence of the forest they occupy. So you can imagine wild animals suffering from the condition of their forests being damaged by various causes such as illegal logging, forest fires, excessive log harvest or the shrinking of forest land for non-forest needs such as for timber estates, plantations, urban expansion, transportation networks and other infrastructure development. Forest land that is far from human settlements will make wildlife very comfortable living in their habitat, but on the other hand it will be very uncomfortable if it is near settlements. This is something that cannot be avoided because the world's population continues to increase in need of shelter, food, clothing, mobility, etc. which in the end will encourage the change of function from forest to non-forest in the name of national development.

Indonesia is a country with a high biodiversity consisting of various islands with a wide variety of coverage in which a very diverse range of flora, fauna and microbes live. Biogeographically, Indonesia has a strategic position in terms of the wealth and diversity of animals and plants. The Indonesia islands of Sulawesi, Maluku, Halmahera, Flores Islands, and the small islands in Nusa Tenggara are located within a transitional area (Wallace's line). The diversity of wildlife species is still quite high in Indonesia and spread over several types of habitats. These wildlife are a natural resource that can be utilised by human, including for ecological purpose.

One of the endemic wild animals that must be protected in both quantity and species is the cuscus. The status of cuscus according to CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora) is almost extinct, and it includes this rare animal in its Appendix II, while IUCN (International Union for Conservation of Nature and Natural Resources) put it in the category endangered species (IUCN, 2008). The population and habitat of cuscus in Indonesia continues to decline with the main threat being illegal hunting. According to Ellen (2012), cuscus is decreasing because a lot of it is consumed, traded, and in the Nuaulu tribe on Seram Island, cuscus is still needed for traditional ritual events.

The marsupial family Phalangeridae is a monophyletic group that includes \(\ge\) 17 living species, all of which are partly or wholly arboreal omnivores or herbivores (Flannery et al., 1987). The Phalangeridae has the most extensive range of any Australasian family of marsupials and occurs in Australia, Tasmania, Papua New Guinea, and throughout island east of Wallace’s Line as far as the Solomon Islands (George 1987). The Indonesian island of Sulawesi from the northwestern limit of its distribution (Flannery et al 1987; George, 1987).

According to Petocz (1994), in Papua, there are five cuscus species: Phalanger orientalis (eastern cuscus), Phalanger gymnotis (the ground cuscus / large tooth cuscus), Spilocuscus maculatus (spotted cuscus, this name is revised to Spilocuscus rufoniger) and Phalanger vestitus (silk hair cuscus). These three species can also be found on the surrounded satelite islands in Papua such as Waigeo, Moor and Numfor. Further to species diversity, Menzies (1991), suggested that there is also S. papuensis (Waigeo cuscus, Waigeo island cuscus) which is an endemic species on Waigeo Island of Raja Ampat. Aplin and Helgen (2008) also described S. wilsoni (spotted cuscus Biak Island) - an endemic cuscus on the islands of Biak and Supiori.

The use of wild animals for trading purposes has long been carried out physically, among others in the form of meat, skin and other body parts that have economic value, while aesthetically, such as for the attraction and maintenance of wild animals that show the physical beauty, sound and character of the species. The tendency to use wild animals, either directly or indirectly for economic reasons and pleasure, has put pressure and has an impact on the quality and quantity of wildlife populations in natural habitats. As a result of further pressure (over exploitation) that lasts for quite a long time and simultaneously has threatened the existence of several wildlife species in natural habitats. The threat to wildlife populations in the IUCN List of Red Book 2000 is divided into levels: Extinct (EX), Critically Endangered (CR), Endangered (EN), and Vulnerable (VU). In reality, over- harvesting/exploitation to utilize wild animals is still taking place more dominantly than conservation efforts. Therefore, aspects of the use and conservation of wild animals should consider proportionality, which will have a negative impact on the ecological balance and will cause damage to nature, which in turn will harm humans themselves.

The cuscus animal is a protected animal, regulated in Government Regulation Number P.106, year 2018 concerning Protected Types of Plants and Animals. Although it is a protected species, hunting and catching of cuscus is still ongoing. Hunting results are generally sold for public consumption because it is one of the sources of animal protein favored by the community (Kunda, 2017a).

The cuscus is a type of marsupial belonging to the Phalangeridae family and is described as a rather large and sturdy animal with a body length the size of a two-month-old pig. It was further explained that the sac in female animals is well developed, opens forward and has four nipples. Menzies (1991) described the cuscus as having a round head, having wool- like fur and being solitary, arboreal and nocturnal. Meanwhile, according to Flannery (1995a) cuscus (Phalangersp) is a large arboreal herbivore species (usually reaching a body weight of more than two kilograms) and utilizes leaves, fruit, flowers and tree bark as a source of food. Cuscus is one of five families belonging to the order Diprotodonta, namely the Phalangeridae family (Menzies, 1991). The distribution of the gray cuscus species (Phalanger) is very wide throughout the lowland rain forest of Papua up to an altitude of 1500 m above sea level. Meanwhile, the distribution of cuscus in Maluku includes Seram Island, Ambon Island, Buru, Banda, Saparua Island, Nusalaut, Haruku Island, Romang, Wetar, Tanimnar and Babar Island.

Various plant species exist in the Papua region and based on Kartikasari, et al. (2013) it is estimated that around 15,000 - 20,000 species. These species are selected by wildlife and consumed as a source of nutrients for cuscus. Types of food, both forest plants and agricultural / plantation plants, are used as a source of food to meet production and reproduction needs in addition to the main life of animals. Apart from plants, protein requirements for cuscus are also obtained from insects and other feed sources of protein.