Ruwenzori black forehead thug
| Ruwenzori black forehead thug | ||||||||||||
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| Cephalophus rubidus | ||||||||||||
| Thomas , 1901 |
The Ruwenzori black- forehead duiker ( Cephalophus rubidus ), also called Ruwenzori duiker , is a type of duiker from central Africa. It is limited to the Ruwenzori Mountains , where it is one of the few larger mammals on the African continent that inhabits extremely high altitudes up to 4200 meters above sea level. The deep red-brown color and the woolly fur are striking. There is hardly any information about the way of life of the animals. The duiker species has long been considered a subspecies of the black-headed duiker, some of which also occurs in the region. However, genetic analyzes speak rather for an independence of the Ruwenzori black-headed dog. It was scientifically described at the beginning of the 20th century. Since its habitat is largely restricted to the Rwenzori Mountains National Park , the population is considered to be endangered.
features
Habitus
The Ruwenzori black forehead duiker is a medium-sized duiker. It has a head-torso length of around 75 cm, plus a tail that is around 10 cm long. The shoulder height is around 45 cm, while the weight is around 15 kg. The duiker species has a dense and rather woolly fur, longer and coarser hairs appear on the neck. The fur is shiny and intensely reddish-brown on the back, and it becomes increasingly lighter on the sides. On the center line of the back, a brown stripe runs from the nape of the neck to the base of the tail, which is created by hair with a reddish brown tip and a brown base. The belly and chest are tinted whitish, as is the entire undercoat. The color of the front legs corresponds to the back, but the joints are highlighted by dark brown markings. The hind legs, however, including the hooves, are colored black. In contrast to the black forehead duiker , the legs and hooves are proportionally not that long. The bushy tail is more black on the top, white on the underside, and white tones also appear on the tip of the tail. The head color hardly differs from the reddish brown of the back, a black or dark brown stripe that runs from the nose to the forehead appears conspicuous. In contrast to this is the whitish chin. As with all ducks, horns occur in both sexes, they reach lengths of 8 to 9 cm.
Skull features
The average length of the skull in males is 17.2 cm and in females 18 cm. The dentition consists of 32 teeth and has the following dental formula : .
distribution
The distribution area of the Ruwenzori black-forehead duiker is limited to the Ruwenzori Mountains in western Uganda . An occurrence on the Virunga volcanoes , where the black- forehead duiker ( Cephalophus nigrifrons ) occurs, has not yet been confirmed. As a rule, the duiker species can be found in mountain heights of 1300 to 4200 m, and it is often seen just below the snow line. The habitat consists of hagenia -Waldlandschaften, at lower altitudes and from bamboo -Pflanzengemeinschaften. The Ruwenzori black forehead duiker occurs predominantly in wetlands that are covered with sedges , or in moor areas in which immortelle , lady's mantle , lobelia or dendrosenecio dominate. Occasionally it is also spotted in meadow landscapes interspersed with heather and on rocky slopes.
Way of life
The way of life of the Ruwenzori black-headed duiker is as good as unexplored. As one of the few larger mammals in Africa, it is adapted to extremely high mountain locations and therefore tolerates very low night temperatures and intense sunshine as well as extremely humid weather. This makes it comparable to other high mountain specialists such as the gray goral ( Naemorhedus goral ) or the chamois ( Rupicapra rupicapra ). Due to the shorter legs and hooves, the species is not as well adapted to wet terrain as the black-forehead duiker. The animals are mostly diurnal, but can also appear at night in unfavorable weather conditions such as rain. It is therefore possible that the individual activity phases are more dependent on the season. They usually enter more open areas such as meadows during the twilight phases. As a rule, the Ruwenzori black forehead duiker occurs individually and lives territorially. In terms of diet, it is probably more like the representatives of the black-headed duck, which occur in the higher elevations of the Virunga volcanoes than in the lowlands to the west. As with the former likely to make due to the greater scarcity of fruits rather leaves , herbs and lichen the main food. Nothing is known about the reproductive behavior.
Systematics
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Internal classification of the genus Cephalophus according to Johnston et al. 2012
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The Ruwenzori black forehead duiker is a species from the genus Cephalophus and the horned bearer family (Bovidae). Within the horn-bearers, Cephalophus is placed in the tribe of the duiker (Cephalophini), to which two other genera belong with Sylvicapra and Philantomba . The duikers are mostly small to medium-sized representatives of the horn-bearers, which have a compact build and are endemic in Africa . With the exception of the genus Sylvicapra , whose members inhabit savannah landscapes , the duikers are mainly adapted to wooded habitats .
Cephalophus represents the most species-rich group within the duiker. A molecular genetic study from 2001 assigned the individual species of the genus a total of three lines of development. One line includes the giant duiker with the Jentink duiker ( Cephalophus jentinki ) and the black- backed duiker ( Cephalophus dorsalis ). The diverse red duiker, on the other hand, form two groups, on the one hand the West African red duiker, so the Petersducker ( Cephalophus callipygus ) and the Ogilby duiker ( Cephalophus ogilbyi ), on the other hand the East African red duiker, such as the Natal red duiker ( Cephalophus natalensis ) and the Harvey red duiker ( Cephalophus harveyi ). This tripartite division of the genus Cephalophus could in principle be confirmed by a later study published in 2012. It also showed that the splitting of the East African red duiker occurred around the transition from the Pliocene to the Pleistocene around 2.4 to 1.2 million years ago. As a further result of the genetic investigations, however, Sylvicapra turned out to be the sister group of the giant duikers, making the genus Cephalophus paraphyletic . Possibly, therefore, the red duiker must be removed from Cephalophus , as a possible new genus name Cephalophorus was proposed.
Due to its external characteristics, the Ruwenzori black forehead duiker was often assigned to the black forehead duiker ( Cephalophus nigrifrons ) as a subspecies in the course of the 20th century . However, it was also partly assumed that the Ruwenzori black forehead duiker is an independent species that differs from the black forehead duiker due to its darker color, the white undercoat and the less pronounced long legs. The species may have been pushed into the higher elevations of the Ruwenzori Mountains by the arrival of the black-headed duck. In contrast to this opinion, the aforementioned genetic study from 2001 revealed that the Ruwenzori black-forehead duiker is not more closely related to the East African red duiker, but to the West African. As a result, she recommended recognizing the Ruwenzori black-forehead duiker as a separate species. Since the examined material only consisted of a single tooth from the Natural History Museum in Stockholm, the suspicion of incorrect identification of the object was expressed. In their general revision of the hornbeams from 2011, Colin Peter Groves and Peter Grubb raised the Ruwenzori black-forehead duiker to its own species status. Regarding the possible genetic relationship with the West African red duckers, however, they note: this is such a surprising result that it must surely be questioned as to whether the specimen from which they obtained their sample really was C. rubidus (“this is such a surprising result that the question must certainly be asked whether the piece from which they [the researchers] took their sample was actually C. rubidus ”). Further genetic tests confirmed the previous results for the time being. The Ruwenzori black forehead duiker is possibly close to the black duiker ( Cephalophus niger ).
The first scientific description of the Ruwenzori black forehead duiker comes from Oldfield Thomas from 1901. He carried it out on an individual who was missing the head. The animal came from the Ruwenzori district and was bought by Henry Hamilton Johnston during an expedition to the region the previous year from the local residents. The area is considered a type region of the species. Thomas recognized a close relationship to the black-forehead duiker, but also noticed clear differences in the thicker and woolier fur and the deeper coloring.
Threat and protection
In the 1960s to 1990s, the Ruwenzori black-forehead duiker was subject to high hunting pressure, especially from the Bakonjo from the surrounding areas. This was alleviated by the establishment of the Rwenzori Mountains National Park in 1991. It is possible that only a few thousand individuals are still alive, most of which are confined to the national park. The survival of the species is therefore dependent on the effective protective measures in this area. The IUCN classifies the Rwenzori black-fronted duiker as "high risk" ( endangered one).
literature
- Colin P. Groves and David M. Leslie Jr .: Family Bovidae (Hollow-horned Ruminants). In: Don E. Wilson and Russell A. Mittermeier (eds.): Handbook of the Mammals of the World. Volume 2: Hooved Mammals. Lynx Edicions, Barcelona 2011, ISBN 978-84-96553-77-4 , p. 773
- Jonathan Kingdon: Cephalophus nigrifrons Black-fronted Duiker. In: Jonathan Kingdon, David Happold, Michael Hoffmann, Thomas Butynski, Meredith Happold and Jan Kalina (eds.): Mammals of Africa Volume VI. Pigs, Hippopotamuses, Chevrotain, Giraffes, Deer and Bovids. Bloomsbury, London, 2013, pp. 253-254
Individual evidence
- ↑ a b J. St. Leger: A key to the species and subspecies of the subgenus Cephalophus. Proceedings of the Zoological Society of London 1936, pp. 209-228
- ↑ a b c d e f Jonathan Kingdon: Cephalophus nigrifrons Black-fronted Duiker. In: Jonathan Kingdon, David Happold, Michael Hoffmann, Thomas Butynski, Meredith Happold and Jan Kalina (eds.): Mammals of Africa Volume VI. Pigs, Hippopotamuses, Chevrotain, Giraffes, Deer and Bovids. Bloomsbury, London, 2013, pp. 253-254
- ↑ a b c d e Colin P. Groves and David M. Leslie Jr .: Family Bovidae (Hollow-horned Ruminants). In: Don E. Wilson and Russell A. Mittermeier (eds.): Handbook of the Mammals of the World. Volume 2: Hooved Mammals. Lynx Edicions, Barcelona 2011, ISBN 978-84-96553-77-4 , p. 773
- ↑ a b c d e Anne R Johnston and Nicola M Anthony: A multi-locus species phylogeny of African forest duikers in the subfamily Cephalophinae: evidence for a recent radiation in the Pleistocene. BMC Evolutionary Biology, 12, 2012, p. 120 ( [1] )
- ↑ a b Bettine Jansen van Vuuren and Terence J. Robinson: Retrieval of Four Adaptive Lineages in Duiker Antelope: Evidence from Mitochondrial DNA Sequences and Fluorescence in Situ Hybridization. Molecular Phylogenetics and Evolution 20 (3), 2001, pp. 409-425
- ↑ Alexandre Hassanin, Frédéric Delsuc, Anne Ropiquet, Catrin Hammer, Bettine Jansen van Vuuren, Conrad Matthee, Manuel Ruiz-Garcia, François Catzeflis, Veronika Areskoug, Trung Thanh Nguyen and Arnaud Couloux: Pattern and timing of diversification of Cetartiodactalia, Lauriala (Mammia ), as revealed by a comprehensive analysis of mitochondrial genomes. Comptes Rendus Palevol 335, 2012, pp. 32-50
- ^ Colin Groves: Current taxonomy and diversity of crown ruminants above the species level. Zitteliana B 32, 2014, pp. 5-14
- ^ Ernst Schwarz: Notes on African ungulates. The Annals and magazine of natural history, 8 (13), 1914, pp. 491–495 ( [2] )
- ↑ Colin P. Groves and Peter Grubb: Ungulate taxonomy. Johns Hopkins University Press, Baltimore 2011, pp. 1-317 (p. 275) ISBN 978-1-4214-0093-8
- ↑ S. Ntie, AR Johnston, P. Mickala, AE Bowkett, B. Jansen van Vuuren, M. Colyn, P. Telfer, F. Maisel, O. Hymas, RL Rouyer, RA Wallace, K. LeBlanc, N. van Vliet, G. Sonet, E. Verheyen, D. Pires, EJ Wickings, SA Lahm and NM Anthony: A molecular diagnostic for identifying central African forest artiodactyls from faecal pellets. Animal Conservation 13, 2010, pp. 80-93
- ↑ Oldfield Thomas: On the more notable mammals obtained by Sir Harry Johnston in the Uganda Protectorate. Proceedings of the Zoological Society 1901 (Vol. 2), pp. 85-90 ( [3] )
- ^ IUCN SSC Antelope Specialist Group: Cephalophus nigrifrons ssp. rubidus. The IUCN Red List of Threatened Species. Version 2015.2. ( [4] ); last accessed on July 20, 2015
Web links
- Cephalophus nigrifrons ssp. rubidus inthe IUCN Red List of Threatened Species 2015.2. Listed by: IUCN SSC Antelope Specialist Group, 2008. Retrieved July 20, 2015.