Variable sun squirrel
| Variable sun squirrel | ||||||||||||
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Variable sun squirrel ( Heliosciurus mutabilis ); Illustration from Wilhelm Peters' travelogue from 1852 |
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| Scientific name | ||||||||||||
| Heliosciurus mutabilis | ||||||||||||
| ( Peters , 1852) |
The variable sun squirrel ( Heliosciurus mutabilis ) is a species of squirrel from the genus of the sun squirrel ( Heliosciurus ). It occurs in large parts of East Africa from southern Tanzania via Zambia and Malawi to Mozambique .
features
The variable sun squirrel is a medium-sized to large squirrel of the genus and reaches an average head-trunk length of about 21.7 to 26.9 centimeters, the tail is about 23.5 to 30.2 centimeters long and the weight is around 330 to 380 grams. The females are on average slightly smaller than the males. The rear foot length is about 46 to 60 millimeters, the ear length 13 to 19 millimeters. Unlike the other species of the genus, the variable sun squirrel is characterized by a very changeable, variable seasonal coat pattern. The animals generally have a brown to reddish brown, rough coat made up of 15 to 20 millimeters long hair, which can have darker markings in the various subspecies. The back hair is banded with a brown base, two lighter and one sand-colored band in the middle and a creamy white tip. The color of the head, cheeks and legs correspond to the fur on the back, the stomach side is lighter and sharply demarcated from the flanks. The tail is comparatively long with about 112% of the head-trunk length, it is thin and brown and has easily recognizable light cream-white to sand-colored rings. The tip of the tail can be reddish brown to cinnamon in color. When the coat changes, the back color changes to a cinnamon-colored, red-brown or chestnut-brown coat, after which it becomes increasingly pale and black-brown. In many individuals, the coat changes in spots, so that the back coat can represent a mosaic on fresh and older coat. This type of coat change is only known from this species in squirrels.
The basic color of the variable sun squirrel corresponds very closely to the gray -footed squirrel ( Heliosciurus gambianus ) and the red-footed sun squirrel ( Heliosciurus rufobrachium ), but is generally somewhat paler and lighter with clearly defined tail rings and a sharp demarcation between the peritoneum and dorsal fur. The ventral side is also less hairy and significantly shorter than the back. Compared to the red-footed sun squirrel, the legs are never reddish brown. Confusion with some very similar African bush squirrels (genus Paraxerus ), namely the Smith bush squirrel ( Paraxerus cepapi ), the red-bellied bush squirrel ( Paraxerus palliatus ) and the striped bush squirrel ( Paraxerus flavovittis ) is possible.
distribution
The variable sun squirrel occurs in large parts of East Africa from southern Tanzania through eastern Zambia and Malawi to large parts of Mozambique . The distribution area of the Zanj sun squirrel ( Heliosciurus undulatus ) joins in northern Tanzania .
Way of life
The variable sun squirrel lives in evergreen rainforests of the flatlands and mountain regions up to heights of about 2100 meters as well as in denser stands and thickets of Brachystegia and Julbernardia along rivers and in the coastal area.
The species is diurnal and not very social, it usually lives alone or with a single partner. The animals live on trees and build nests in tree hollows or in dense vines in the higher tree layers. They feed mainly on Kigelia fruits and ivy leaves, but also eat other parts of plants, fruits, nuts and also insects and eggs. They run quickly over branches and twigs in the treetops. When threatened, the animals utter loud calls and raise their tails, sometimes they press close to branches or hide in a tree hollow.
There is hardly any data available on reproductive behavior; a female in Zimbabwe was caught pregnant with four pups.
Systematics
The variable sun squirrel is classified as an independent species within the genus of the sun squirrel ( Heliosciurus ), which consists of six species. The first scientific description comes from Wilhelm Peters from 1852. Peters observed a pair of the species during his trip through southern Africa from 1842 to 1848 near Boror 19 kilometers northwest of Quelimane in Mozambique and was able to catch the female. This formed the basis for his scientific description, which he carried out under the name Sciurus mutabilis . Animals were subsequently partially as a subspecies of Graufußhörnchens ( Heliosciurus gambianus ) or the red-footed sun croissant ( Heliosciurus rufobrachium considered).
Within the species, five subspecies are distinguished with the nominate form :
- Heliosciurus mutabilis mutabilis : nominate form; lives in the mountainous regions of southern Tanzania and neighboring Mozambique. The back color is dark brown, the belly side whitish, yellowish or brownish-gray. The tail rings are bright and less noticeable than in the other subspecies. Some individuals have a dark stripe that extends from the forehead over the head and back to the tail and is sometimes widened on the flanks and trunk. Some have a black spot on the back.
- Heliosciurus mutabilis beirae : In the southern altitudes of Tanzania and Mozambique. The subspecies has distinct tail rings and a white belly.
- Heliosciurus mutabilis chirindensis : In the Chirinda Forest in eastern Zimbabwe. The ventral side is sand-colored and white with an ocher-colored tint to darker ocher-colored or gray-brown. The peritoneum is lighter than that of the flanks, the tail rings are clearly formed.
- Heliosciurus mutabilis shirensis : In Zambia and in western Malawi as well as in the extreme southwest of Tanzania and in bordering Mozambique and Zimbabwe. The back fur is paler than that of the nominate form, a black back spot is missing. The legs and the belly are colored white to sand, the tail has 16 light-colored tail rings.
- Heliosciurus mutabilis vumbae : In the mountain regions in the border area of Zimbabwe and Mozambique, the populations are separated from those of the nominate form by about 300 kilometers. The subspecies has a dark color, the belly and back do not differ. The back band is darker and more indistinct than in the nominate form.
Status, threat and protection
The variable sun 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 relatively large distribution area and the assumed large and stable stocks. It is also found in numerous protected areas. There are no known risks to the company's existence. Regionally, in Mozambique in particular, the loss of forest to convert rainforests into agricultural areas and local deforestation for firewood production pose a threat to local populations .
supporting documents
- ↑ a b c d e f g h i j D. CD Happold: Heliosciurus mutabilis, Mutable Sun 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. 64-65; ISBN 978-1-4081-2253-2 .
- ↑ 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; Pp. 225-226. ISBN 978-1-4214-0469-1
- ↑ a b c d Heliosciurus mutabilis in the Red List of Threatened Species of IUCN 2015-4. Posted by: P. Grubb, J. Kerbis Peterhans, 2008. Retrieved January 10, 2015.
- ↑ a b Heliosciurus mutabilis 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 .
- ^ Wilhelm Peters: Scientific trip to Mossambique: executed on the orders of his Majesty the King Friedrich Wilhelm IV in the years 1842 to 1848. Berlin, 1852, pp. 1–205 (pp. 131–134) ( [1] )
literature
- Richard W. Thorington Jr. , John L. Koprowski, Michael A. Steele: Squirrels of the World. Johns Hopkins University Press, Baltimore MD 2012; Pp. 230-231. ISBN 978-1-4214-0469-1
- DCD Happold: Heliosciurus mutabilis, Mutable Sun 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. 64-65; ISBN 978-1-4081-2253-2 .
Web links
- Heliosciurus mutabilis onthe IUCN 2015-4 Red List of Threatened Species . Posted by: P. Grubb, J. Kerbis Peterhans, 2008. Retrieved January 10, 2015.