Pale giant squirrel
| Pale giant squirrel | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Ratufa affinis | ||||||||||||
| ( Raffles , 1821) |
The pale giant squirrel ( Ratufa affinis ) is a type of squirrel from the genus of the giant squirrel ( Ratufa ). It occurs in Southeast Asia in southern Thailand , Singapore and on the Malay Peninsula as well as on Sumatra and Borneo .
features
The pale giant squirrel reaches a head-torso length of about 33.5 to 34.5 centimeters and a weight of about 1000 to 1250 grams. This makes it one of the largest squirrel species worldwide, along with other species of the genus and representatives of other genera. The tail reaches a length of 40 to 42.5 centimeters and is thus slightly longer than the rest of the body. The fur of the animals is brown in color, while it is pale brown in the area of the abdomen and darker on the back, at least in the area of the midline.
| 1 | · | 0 | · | 1 | · | 3 | = 20 |
Like all species of the genus has the type in the upper jaw half per one to a incisor tooth formed incisor (incisor) to which a tooth gap ( diastema follows). This is followed by a premolar and three molars . The teeth in the lower jaw correspond to those in the upper jaw. In total, the animals have a set of 20 teeth.
distribution
The pale giant squirrel is found in South and Southeast Asia in southern Thailand , Singapore and the Malay Peninsula, as well as on Sumatra , Borneo and some surrounding small islands.
Way of life
Little data or observations are available on the pale giant squirrel's way of life. Like all species of the genus, it is largely tree-living ( arboricol ) and lives in the tropical rainforests of the range. The animals prefer heights of 20 to 40 meters and live in the canopy. They rarely or never get to the forest floor. The animals rarely use plantations and secondary forests .
The squirrels feed mainly on seeds and occasionally on fruits, plant juices or bark. They rarely use flowers and leaves as food. It is assumed that the population density of the squirrels is very low due to the competition with birds and especially primates for food. The animals build spherical nests from twigs and small branches in the high treetops.
Systematics
The pale giant squirrel is classified as an independent species within the genus of the giant squirrel ( Ratufa ), which consists of four species. The first scientific description comes from Thomas Stamford Raffles from 1831, who described an individual from Singapore.
Within the species, a total of nine subspecies are distinguished using the nominate form :
- Ratufa affinis affinis : nominate form; Found in Thailand, the Malay Peninsula and Singapore. It is light on the underside and uniformly brown on the back, with individuals in the south being lighter.
- Ratufa affinis bancana : Occurrence on the Indonesian Isel Bangka east of Sumatra.
- Ratufa affinis baramensis : Occurrence in Sabah and Sarawak on Borneo, the Malay island of Pulau Banggi and the northeast of Kalimantan
- Ratufa affinis bunguranensis : Occurrence on the northern Natuna Islands between the Malay Peninsula and Borneo.
- Ratufa affinis cothurnata : Occurrence in western Kalimantan.
- Ratufa affinis ephippium : Occurrence in southeastern Kalimantan.
- Ratufa affinis hypoleucos : Occurrence on Sumatra.
- Ratufa affinis insignis : Occurrence on the Indonesian Riau Islands .
- Ratufa affinis polia : Occurrence on the Indonesian island of Belitung .
Status, threat and protection
The pale giant squirrel population in Southeast Asia is significantly declining, with the rate of decline estimated to be less than 30 percent of the population over the past decade. According to a mapping from 2004, the species is the most common giant squirrel species on the Malay Peninsula with a population density of 1.3 (± 0.61) individuals per km 2 . In forest areas not affected by logging, the population rate is moderate, in 2001 surveys in the Danum Valley in Sabah it was an average of 3.61 individuals per km 2 , in 1996 in Nanga Gaat in Sarawak an average of 5.18 individuals per km 2 were determined.
The main threats to the pale giant squirrel include deforestation, although the species is likely already responding to selective logging, as well as hunting. It is classified as Near Threatened by the International Union for Conservation of Nature and Natural Resources (IUCN). The reason is the clear decline in populations due to hunting and the heavy loss of habitat of the species in most of its range.
supporting documents
- ↑ a b c d e f g h Richard W. Thorington Jr. , John L. Koprowski, Michael A. Steele: Squirrels of the World. Johns Hopkins University Press, Baltimore MD 2012, ISBN 978-1-4214-0469-1 , pp. 23-24 .
- ^ Robert S. Hoffmann, Andrew T. Smith: Ratufa. In: Andrew T. Smith , Yan Xie: A Guide to the Mammals of China. Princeton University Press, Princeton NJ 2008, ISBN 978-0-691-09984-2 , p. 173.
- ↑ a b c d e f g h i Ratufa affinis in the Red List of Threatened Species of the IUCN 2014.2. Listed by: JW Duckworth, E. Meijaard, B. Giman, KH Han, 2008. Retrieved October 13, 2014.
- ↑ a b c Ratufa affinis In: Don E. Wilson , DeeAnn M. Reeder (Ed.): Mammal Species of the World. A taxonomic and geographic Reference. 2 volumes. 3. Edition. Johns Hopkins University Press, Baltimore MD 2005, ISBN 0-8018-8221-4 .
literature
- Richard W. Thorington Jr. , John L. Koprowski, Michael A. Steele: Squirrels of the World. Johns Hopkins University Press, Baltimore MD 2012, ISBN 978-1-4214-0469-1 , pp. 23-24 .
Web links
- Ratufa affinis inthe IUCN Red List of Threatened Species 2014.2. Listed by: JW Duckworth, E. Meijaard, B. Giman, KH Han, 2008. Retrieved October 13, 2014.