Giant squirrel
| Giant squirrel | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
King Giant Squirrel ( Ratufa indica ) |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name of the subfamily | ||||||||||||
| Ratufinae | ||||||||||||
| Moore , 1959 | ||||||||||||
| Scientific name of the genus | ||||||||||||
| Ratufa | ||||||||||||
| JE Gray , 1867 |
The giant squirrels ( Ratufa ) are a genus of South Asian squirrels with four species. Together with the marmots and the giant sliding squirrels, they are among the largest squirrels in the world. Relatively, they are compared to all other squirrels as a separate subfamily Ratufinae .
features
The giant squirrels are one of the largest species of squirrel in the world and have a head-to-trunk length of 25 to 45 centimeters, making them larger than a marten . The weight can be up to two kilograms, in exceptional cases three kilograms. This means that giant squirrels are exceptionally large members of the family, but there are even larger squirrels among the flying squirrels. The tail is longer than the head-trunk length. The species have a brightly colored fur. The black giant squirrel is colored black on the top and yellow on the underside. The king's giant squirrel has a dark red surface, black spots on the back, shoulders and legs, and a whitish-yellow underside. The feet are very strong and have sharp claws. The females have three pairs of teats.
| 1 | · | 0 | · | 1 | · | 3 | = 20 |
The skull of the animals is strongly built, the snout region is very short. The length of the nasal bones corresponds to about half the maximum width of the skull in the area of the zygomatic arches . The frontal bone is long and wide, the postorbital process is blunt. The occipital region is compressed. All species of the genus have a a maxillary per half 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
Of the giant squirrel species, the king's giant squirrel ( Ratufa indica ) and the Sri Lankan giant squirrel ( Ratufa macroura ) are restricted to India and Sri Lanka . The black giant squirrel ( Ratufa bicolor ) occurs over large parts of South and Southeast Asia from Nepal and the People's Republic of China to the Indonesian islands. The distribution area of the pale giant squirrel ( Ratufa affinis ) includes the Malay Peninsula and the islands of Sumatra and Borneo .
Way of life
Giant squirrels inhabit the canopy region of the tropical rainforest . Here they are very lively and jump through the branches with up to six meter long sentences. They come to rest in tree hollows, and only when they reproduce do they build a nest from parts of the plant in the branches. These nests can take on enormous dimensions and have a diameter of almost two meters. As with most arboreal croissants, the food consists of nuts, fruits and bark, and occasionally bird eggs. Unlike most squirrels, giant squirrels cannot sit on their hind legs and maintain their balance.
As loners, giant squirrels only come together at the mating season and then part again immediately. After a gestation period of thirty days, one to five young are born who do not reach sexual maturity until they are two years old. A giant giant squirrel lived to be twenty years old in captivity, which is an exceptionally old age for a rodent.
Systematics
The giant squirrels form their own subfamily within the squirrels, which contains only a single genus with the genus Ratufa . The genus Ratufa was first described by John Edward Gray in 1867. Traditionally, the giant squirrels were systematically placed in the vicinity of the beautiful squirrels . In 1959, in his revision of the croissant system, Joseph Curtis Moore introduced the giant squirrels as a separate tribe Ratufini, to which he assigned the Ratufa species. In recent years, cladistic analyzes have shown that giant squirrels among the squirrels living today have no close relatives and are evidently to be regarded as a sister group of all other squirrels, they are therefore managed in their own subfamily.
There are four types of giant squirrels:
- Pale giant squirrel ( Ratufa affinis ) in the Malay Peninsula , Sumatra and Borneo
- Black giant squirrel ( Ratufa bicolor ) on mainland Southeast Asia as well as on Hainan , Sumatra , Java and Bali
- King Giant Squirrel ( Ratufa indica ) in India
- Sri Lankan Giant Squirrel ( Ratufa macroura ) in southern India and Sri Lanka
Threat and protection
The populations of all giant squirrels have declined significantly in recent years, which is why the International Union for Conservation of Nature and Natural Resources (IUCN) has classified all four species as " near threatened ".
The Sri Lankan giant squirrel once had a larger distribution in southern India, but has become extinct there except for a few hundred specimens, so that it is almost only found in Sri Lanka. Of four subspecies of the king giant squirrel, one is already extinct, the Dangs giant squirrel ( Ratufa indica dealbata ), which lived in Gujarat and has not been seen since the 1940s.
supporting documents
- ^ A b c Robert S. Hoffmann, Andrew T. Smith: Subfamily Ratufinae / Genus 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.
- ^ Joseph Curtis Moore : Relationship among living squirrels of the Sciurinae. Bulletin of the American Museum of Natural History 118, 1959; Pp. 153-206.
- ↑ Ratufinae In: Richard W. Thorington Jr., John L. Koprowski, Michael A. Steele: Squirrels of the World. Johns Hopkins University Press, Baltimore MD 2012; P. 23 ff. ISBN 978-1-4214-0469-1
- ^ JL Koprowski, EA Goldstein, KR Bennett, C. Pereira Mendes: Subfamily Ratufinae, Genus Ratufa. In: Don E. Wilson, TE Lacher, Jr., Russell A. Mittermeier (Eds.): Handbook of the Mammals of the World: Lagomorphs and Rodents 1. (HMW, Volume 6) Lynx Edicions, Barcelona 2016, ISBN 978- 84-941892-3-4 , pp. 711-714.
literature
- JL Koprowski, EA Goldstein, KR Bennett, C. Pereira Mendes: Subfamily Ratufinae, Genus Ratufa. In: Don E. Wilson, TE Lacher, Jr., Russell A. Mittermeier (Eds.): Handbook of the Mammals of the World: Lagomorphs and Rodents 1. (HMW, Volume 6) Lynx Edicions, Barcelona 2016, ISBN 978- 84-941892-3-4 , pp. 711-714.
- Robert S. Hoffmann, Andrew T. Smith: Subfamily Ratufinae / Genus 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.
- 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. 25th ff .
- Ronald M. Nowak: Walker's Mammals of the World. 2 volumes. 6th edition. Johns Hopkins University Press, Baltimore MD et al. 1999, ISBN 0-8018-5789-9 .
- Michael D. Carleton, Guy G. Musser: Order Rodentia. In: Don E. Wilson , DeeAnn M. Reeder (Eds.): 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 , pp. 745-1600.
Web links
- Search for "Ratufa" in the IUCN Red List of Threatened Species .