Boehm bush squirrel
| Boehm croissant | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Paraxerus boehmi | ||||||||||||
| ( Reichenow , 1886) |
The Böhm squirrel or Böhm bush squirrel ( Paraxerus boehmi ) is a species of squirrel from the genus of the African bush squirrel ( Paraxerus ). It occurs in Central Africa from the east of the Democratic Republic of the Congo via Uganda , South Sudan and the northwest of Tanzania to the north of Zambia . The little squirrels live mainly in the tropical rainforest and feed mainly on insects and parts of plants.
features
The Böhm croissant is a small croissant and reaches an average head-trunk length of around 11.1 to 12.6 centimeters (according to Thorington et al. 2012, up to 12.9 centimeters), the tail is around 14.0 to 16 cm , 0 centimeters long. The weight is around 48 to 80 grams, with the females being a bit heavier. The rear foot length is around 28 to 34 millimeters, the ear length 11 to 14 millimeters. The coloring of the animals varies regionally with the different subspecies. The animals have a grayish reddish to yellowish brown back fur on which there are four black stripes and which appears olive-brown at a distance. The middle two stripes are separated by a reddish-brown back stripe on the spine from the shoulders to the torso, laterally the dark stripes are separated again by narrow cream-white to yellow side stripes. The peritoneum corresponds to the fur on the back, but is a little paler. The head also has the same color as the fur on the back and is marked by three light stripes, sometimes difficult to see, one above and one below the eyes and one on the cheeks. The ears are small and rounded; in contrast to related species, they have no white border and no other white components. The front and rear legs are greenish-brown. The front feet have four long toes, each ending in a long, sharp claw. The hind feet have five toes, which are also equipped with long claws. The tail is comparatively long with a length of about 125% of the head-trunk length. It is very hairy and colored black to ocher, it is marked by irregular dark stripes and tapers towards the end.
| 1 | · | 0 | · | 2 | · | 3 | = 22 |
| 1 | · | 0 | · | 1 | · | 3 |
The skull has a total length of 33.9 to 36.6 millimeters and a width of 18.1 to 21.7 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 row of molars from the first premolar to the third molar is 5.3 to 6.4 millimeters. The bony palate ends at the level of the third molar.
The Böhm squirrel is similar to the Alexander bush squirrel ( Paraxerus alexandri ), but is much larger and differs in details in terms of color. The Alexander bush squirrel has only two instead of four dark stripes on its back, which are laterally bordered by a creamy white line, and a white border around the ears. The feet of the Alexander bush squirrel are also significantly larger and stronger in relation to the body. Confusion with the banded redshank squirrel ( Funisciurus lemniscatus ) with a similar distribution area and also four dark back stripes is possible, but this is somewhat larger and darker in color. The tail of the banded redshank squirrel is longer and stronger. It also lives mainly on the ground and not in the branches of the trees.
distribution
The Böhm croissant occurs in Central Africa from the east of the Democratic Republic of the Congo via Uganda , South Sudan , Rwanda , Burundi and the northwest of Tanzania to the north of Zambia . The subspecies P. b. vulcanorum occurs in the mountain forests of the Albert Graben , occurrences in western Kenya have not yet been confirmed. A remote population of the species lives in the Bahr al-Ghazal region west of Malek in South Sudan.
Way of life
The Böhm croissant lives in tropical rainforest areas in the lowlands, in swamp areas and also in mountain forests at altitudes of up to 2300 meters. It occurs mainly in forests that are characterized by cynometra from the group of the carob family , which as a climax species sometimes forms large stands. As a rule, the animals live in the undergrowth, in dense lianas and the lower tree areas, and more rarely on the forest floor. In the east of the Democratic Republic of the Congo, the species has also been documented in savannah forests , and it also occurs on the edge of plantations.
The animals are diurnal and, like other bush squirrels, live on trees. They usually live individually, but can also be observed in pairs or trios. Due to their small size and long, clawed toes, the animals are able to quickly climb tree trunks and large branches. You can move up and down and hang upside down to examine the underside of branches. The Böhm croissant usually builds large nests in the branches at a height of around two to eight meters. They mainly consist of twigs, leaves and grass and contain a nest chamber that is lined with finer material such as crushed bark. Communication takes place via fragrances that are distributed with the tail, as well as via bird-like sounds and optical signals through jerky tail movements.
Böhm squirrels are omnivorous , their diet consists mainly of insects and fruits. Foraging takes place alone, but sometimes they look for food close to other individuals. The animals run over the branches and examine moss pads, lichens and bark with their incisor teeth, whereby, unlike many other croissants, they hardly use their front legs to search. With their snouts and incisors, they can lift and split bark to catch insects underneath. In studies of the stomach contents of 30 animals in Uganda, the stomachs of seven animals contained only insects, mainly ants and, to a lesser extent, caterpillars and beetles. Ten stomachs were mostly filled with insects and eight only contained traces of insects. Plant and fungal remains, such as the fruits of Rubus species and epiphytic fungi, were found in 12 of the stomachs , and large amounts of tree resin were found in ten stomachs. Stomach exams in the Democratic Republic of the Congo gave similar results.
Reproduction occurs year-round in rainy areas in the Democratic Republic of the Congo, with the rate of pregnant females at various times being 10 to 35% of the total number of females. The highest reproduction rate is at the end of the dry season just before the annual rainfall. For Uganda, catch data are also available with pregnant females at different months. The litters usually consist of one and less often two young animals. Due to the distribution of births over the entire year, the age structure is very much characterized by young animals and young sexually mature animals.
The most important predators include birds of prey, especially the long-tailed goshawk ( Urotriorchis macrourus ), as well as hornbills and snakes. In addition, there are nocturnal predators such as the genet cats ( Genetta ) and the leopard roller ( Nandinia binotata ), which track the animals in the nest.
Systematics
The Böhm 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 Anton Reichenow from 1886, who described the species as Sciurus boehmi using individuals from Marungu in the Democratic Republic of the Congo. The species was named after the German naturalist Richard Böhm .
Within the species, four subspecies are distinguished with the nominate form :
- Paraxerus boehmi boehmi : nominate form; occurs in the south of the Democratic Republic of the Congo. The back is olive-brown with a black wash. The individual hairs are grayish black at the base with olive and golden brown rings at the top. The central stripe is olive-golden brown, the outer light stripes whitish. The underside of the body and the inside of the arms and hips are yellowish-white, the throat is pale yellow and the chin is yellowish rust-red.
- Paraxerus boehmi antoniae : in the area around the Boyoma Falls in the Democratic Republic of the Congo. The basic color of the animals is pale greenish-yellow-brown. The middle stripe on the back is more yellowish, the two outer light stripes are more yellowish white and do not begin until the loin. The belly side is washed in light yellow-sand-colored.
- Paraxerus boehmi emini : in the largest part of the distribution area, largely corresponds to the general description of the species, with the middle stripe on the back being more whitish olive green.
- Paraxerus boehmi gazellae : in the eastern Equatoria in South Sudan. The body color is paler and grayer than Paraxerus boehmi emini , the back stripes are shorter and the outer stripe is only about 2.5 centimeters long. The underside of the body is greyish with a slight olive-colored wash.
Kingdon 2013 also describes four subspecies, but Paraxerus boehmi antoniae is not a subspecies of its own and Paraxerus boehmi vulcanorum is listed as a fourth subspecies:
- Paraxerus boehmi vulcanorum : This subspecies occurs in the mountain forests of the Albert Trench in the Ruwenzori Mountains and the mountains between Lake Eduard and Lake Tanganyika . The back color is darker olive-brown and reddish olive-colored, the back fur is long and dense. The upper dark stripe is wide, the lower one very narrow and the white stripes separating it are very inconspicuous. It may be a species of its own.
Status, threat and protection
The Böhm croissant 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. The Böhm croissant is a regularly occurring species within its distribution area, and there are no known risks to its existence.
supporting documents
- ↑ 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. 234-235. ISBN 978-1-4214-0469-1
- ↑ a b c d e f g h i j k l m Jonathan Kingdon: Paraxerus boehmi, Boehm'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. 75-77; 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 Paraxerus boehmi in the IUCN 2016-1 Red List of Endangered Species . Posted by: P. Grubb, 2008. Retrieved July 24, 2016.
- ↑ a b Paraxerus boehmi . 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 .
- ↑ Bo Beolens, Michael Grayson, Michael Watkins: The Eponym Dictionary of Mammals. Johns Hopkins University Press, 2009; P. 48; 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. 234-235. ISBN 978-1-4214-0469-1
- Jonathan Kingdon: Paraxerus boehmi, Boehm'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. 75-77; ISBN 978-1-4081-2253-2 .
Web links
- Paraxerus boehmi inthe IUCN 2016-1 Red List of Threatened Species . Posted by: P. Grubb, 2008. Retrieved July 24, 2016.