Alexander bush squirrel
| Alexander croissant | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Paraxerus alexandri | ||||||||||||
| Thomas & Wroughton , 1907 |
The Alexander squirrel or Alexander bush squirrel ( Paraxerus alexandri ) is a species of squirrel from the genus of the African bush squirrel ( Paraxerus ). It occurs in central Africa in the northeast of the Democratic Republic of the Congo and in the west of Uganda . The little squirrels live mainly on tree trunks and large branches in the tropical rainforest and feed mainly on insects and parts of plants.
features
The Alexander croissant is a small croissant and has an average head-trunk length of around 9.1 to 11.4 centimeters, the tail is around 9.3 to 12.6 centimeters long and the weight is around 40 to 72 Gram. The rear foot length is about 23 to 28 millimeters, the ear length 12 to 14 millimeters. The animals have a grayish olive-brown to yellowish dorsal fur on which there are two black stripes, separated by a wide middle tan yellow and flanked by narrow cream-white side stripes; in total there are five stripes on the back. The hair of the back fur is dark gray at the base, followed by a yellow band and a black tip. There is some white hair between these. The peritoneum corresponds to the fur on the back, but is a little paler. and often has irregular yellow spots and lines. The hair here is dark gray at the base with a yellowish tip. The head is also the same color as the fur on the back, the edges of the ears are conspicuously white. The animals have long vibrissae and a white eye ring, which is inconspicuous in many animals. Compared to other squirrels of the same size, the legs are relatively long and greenish-brown. The front feet have four long toes, each ending in a long, sharp claw. The hind feet have five toes, one of which is reduced and the other also have long claws. The tail is long and corresponds approximately to the length of the head and torso. It is densely covered with hair, which is characterized by brown to ocher-colored and light banding. A seasonal color change was found in the animals. Animals caught between November and February were usually lighter in color than those caught between March and October. The females have three pairs of teats .
| 1 | · | 0 | · | 2 | · | 3 | = 22 |
| 1 | · | 0 | · | 1 | · | 3 |
The skull has a total length of 29 to 33 millimeters. 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 two premolars and three molars . The teeth in the lower jaw correspond to those in the upper jaw, but only with a premolar. In total, the animals have a set of 22 teeth.
The Alexander squirrel is similar to the Böhm bush squirrel ( Paraxerus boehmi ), but is slightly smaller and differs in details in terms of color. The Boehm croissant has a total of four instead of two dark stripes on its back and the white border around the ears is missing. Confusion with the banded redshank squirrel ( Funisciurus lemniscatus ) with a similar distribution area is possible, but this is also somewhat larger and generally darker in color and it also has four dark back stripes.
distribution
The Alexander squirrel is found in central Africa in the northeast of the Democratic Republic of the Congo and in the west of Uganda . The distribution area extends from Lualaba in the west to the Kagera Nile in the east and from Mbomou in the north to Lukuga in the south.
Way of life
The Alexander squirrel lives in tropical rain forest areas in the lowlands at heights below 1500 meters in high primary forest regions and in fallow plantations. The occurrence is often connected with the occurrence of Cynometra alexandri from the group of the carob family , which as a climax species sometimes forms large populations.
The animals are diurnal and, like other bush squirrels, live on trees. They usually live singly or in pairs. Due to their small size and long, clawed toes, the animals are able to climb tree trunks and large branches. While they prefer trees with smooth bark against coarse borkigen tribes and can regularly on the trunks of large Cynometra - Mahogany - or Khaya -Trees be observed. They can be found at all altitudes, but can be seen more frequently in the area of the trunks and large branches and less in the area of leaves than other types of squirrels. They sometimes live in hollow branches and tree hollows, but it is not known whether they build nests. It is assumed that they are less sensitive to smells than other species and are accordingly less oriented towards scent traces. The animals are usually quiet, but sometimes a bird-like chirping can be heard. The ear positions probably play an important role in optical communication due to the conspicuous white border.
The animals are omnivorous , their food consists mainly of insects (around 50%), parts of plants and less often of resin, lichens could also make up a certain proportion. They often find their food on the branches and in the bark, only rarely in the canopy of trees. The search for food takes place alone, the animals run across the trees in choppy sequences and always stop briefly when they have found something to eat. Compared to sympatrically occurring Feuerfußhörnchen ( Funisciurus pyrropus ) the proportion of insects in the diet is significantly higher.
Only limited data are available on the reproduction of the animals. Pregnant females were caught in March, April, June, July and September in the Democratic Republic of the Congo and in September and November in Uganda. Young animals were observed in Uganda in April, October and November. The litters usually consist of one, more rarely two young animals. Birds of prey are among the most important predators, but hornbills also play an important role, especially for the animals that live in tree hollows. In addition, there are likely to be snakes as a potential threat.
Systematics
The Alexander squirrel is classified as an independent species within the genus of the African bush squirrel ( Paraxerus ), which consists of eleven species. The first scientific description comes from Oldfield Thomas and Robert Charles Wroughton from 1907 on the basis of two individuals from the River Iri near Gudima in the Democratic Republic of the Congo, the holotype represents a fully grown male with a total length of 22.5 cm. They described the species as Funisciurus alexandri and assigned them to the redshank squirrels . The species was named after the British military and ornithologist Boyd Alexander (1873-1910), who was a researcher in West Africa.
Apart from the nominate form, no further subspecies are distinguished within the species .
Status, threat and protection
The Alexander squirrel is classified by the International Union for Conservation of Nature and Natural Resources (IUCN) as not endangered (“least concern”). This is justified with the large distribution area and the assumed large stocks. It is also found in numerous protected areas and does not show any significant decreases. In the primary forest areas of the distribution area, the species can be found frequently to regularly, after a felling the populations decline rapidly. At times, it was considered to be included in the warning list of endangered species, as the available habitats are declining due to logging and the conversion into agricultural land. Accordingly, it is viewed regionally as endangered.
supporting documents
- ↑ a b c d e f g h i j k l m n o Jonathan Kingdon: Paraxerus alexandri, Alexander's Bush Squirrel. In: Jonathan Kingdon, David Happold, Michael Hoffmann, Thomas Butynski, Meredith Happold and Jan Kalina (eds.): Mammals of Africa Volume III. Rodents, Hares and Rabbits. Bloomsbury, London 2013, pp. 74-75; ISBN 978-1-4081-2253-2 .
- ↑ Peter Grubb: Genus Paraxerus, Bush Squirrels. In: Jonathan Kingdon, David Happold, Michael Hoffmann, Thomas Butynski, Meredith Happold and Jan Kalina (eds.): Mammals of Africa Volume III. Rodents, Hares and Rabbits. Bloomsbury, London 2013, pp. 72-74; ISBN 978-1-4081-2253-2 .
- ↑ a b c d Richard W. Thorington Jr. , John L. Koprowski, Michael A. Steele: Squirrels of the World. Johns Hopkins University Press, Baltimore MD 2012; Pp. 233-234. ISBN 978-1-4214-0469-1
- ↑ a b c Paraxerus alexandri in the Red List of Threatened Species of IUCN 2015-4. Posted by: P. Grubb, 2008. Retrieved February 9, 2016.
- ↑ a b Paraxerus alexandri . 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 .
- ↑ Oldfield Thomas and Robert Charles Wroughton: New mammals from Lake Chad and the Congo, mostly from the collections made during the Alexander-Gosling Expedition. The Annals and magazine of natural history 7 (19), 1907, pp. 370–387 ( [1] )
- ↑ Bo Beolens, Michael Grayson, Michael Watkins: The Eponym Dictionary of Mammals. Johns Hopkins University Press, 2009; P. 7; ISBN 978-0-8018-9304-9 .
literature
- Richard W. Thorington Jr. , John L. Koprowski, Michael A. Steele: Squirrels of the World. Johns Hopkins University Press, Baltimore MD 2012; Pp. 233-234. ISBN 978-1-4214-0469-1
- Jonathan Kingdon: Paraxerus alexandri, Alexander's Bush Squirrel. In: Jonathan Kingdon, David Happold, Michael Hoffmann, Thomas Butynski, Meredith Happold and Jan Kalina (eds.): Mammals of Africa Volume III. Rodents, Hares and Rabbits. Bloomsbury, London 2013, pp. 74-75; ISBN 978-1-4081-2253-2 .
Web links
- Paraxerus alexandri onthe IUCN 2015-4 Red List of Threatened Species . Posted by: P. Grubb, 2008. Retrieved February 9, 2016.