Karoo Cliff Elephant Shrew
| Karoo Cliff Elephant Shrew | ||||||||||||
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| Elephantulus pilicaudus | ||||||||||||
| Smit , 2008 |
The Karoo Cliff elephant shrew ( Elephantulus pilicaudus ), also Karoo elephant shrews or Karoo Elephant Shrew , is a species of elephant shrews from the family of shrews . It is widespread in southern Africa and inhabits stony and rocky areas in the largely dry landscapes of the Nama Karoo . Little is known about the further way of life. The first description of the Karoo Cliff Elephant Shrew took place in 2008. In the new kind attention were researchers by molecular genetic studies of the closely related and also in South Africa domestic Cape Elephant Shrew , where they met with some individuals from the central area of the Karoo on significant deviations . These and other differences ultimately led to these specimens being described as a separate new species. So far, only a total of 17 individuals of the Karoo cliff elephant shrew are known.
description
Habitus
The Karoo Cliff elephant shrew is an approximately medium-sized representative of the elephant shrews and reaches a total length of 22.6 to 26.6 cm, of which the tail takes 11.2 to 15.1 cm. It is therefore the same length or slightly longer than the rest of the body. The weight varies between 38 and 59 g. There are no major differences between male and female animals. Like all elephant shrews, the Karoo cliff elephant shrew is characterized by its small body size, the comparatively large head with the characteristic, trunk-like elongated nose and the very long hind legs compared to the front legs. Outwardly, the species is very similar to the Cape elephant shrew ( Elephantulus edwardii ) and the western cliff elephant shrew ( Elephantulus rupestris ), with which it sometimes occurs sympatric . The fur is very soft, which characterizes all elephant shrews. The back and top of the head are colored gray-brown, interspersed with black-brown hair. The back color runs down the sides of the trunk, which differs from the two sympatric representatives, in which the flanks continuously lighten. The ventral side, on the other hand, shows a spotted yellowish-gray color. A narrow, dark stripe runs along the middle line of the trunk, which becomes lighter towards the head. The ears are relatively large, broad at the base and have a rounded tip. They become 25 to 32 mm long. The back of the ears stands out with a light, yellowish-brown tint, with the hair color continuing to the nape of the neck. It is not as clearly recognizable here as in the western cliff elephant shrew, but more conspicuous than in the Cape elephant shrew. The eyes are large and are framed by a bright eye ring typical of the Elephantulus genus , which appears creamy-yellow in the Karoo cliff elephant shrew. But it is interrupted at the side. The vibrissae are long and dark in color. The tail is dark on top in the front area, lighter on the underside, but completely dark in the rear section. The fur on the tail increases towards the end, the hair here is less than 4 mm long. At the tip of the tail there is a clear tuft of hair consisting of individual hairs over 4 mm long. As with all elephant shrews, the front and rear legs each end in five rays with claws. The rear foot length varies between 23 and 36 mm.
Skull and dentition features
The skull varies in length from 33.2 to 35.1 mm, the snout takes about 15 mm. At the zygomatic arches the skull becomes 18.3 to 20 mm wide, but only 7.1 mm at the constriction behind the orbit . The tympanic bladder is moderately swollen, and the suture between the middle jawbone and the upper jaw is relatively straight. The bit has the following dental formula of: . Thus a total of 40 teeth are formed. The first upper premolar has only one cusp. As in the Cape elephant shrew, the second upper premolar shows a chewing surface pattern with sharp points ( sectorial ), whereas in the western cliff elephant shrew it is molar- shaped.
distribution
The distribution area of the Karoo cliff elephant shrew includes the Nama Karoo of the South African provinces of the North Cape and Western Cape , in the latter, however, the species has only been detected in the northwestern area. The Nama-Karoo is a semi-desert landscape that divides into the Bushmanland and the Upper and Lower Karoo. The Karoo cliff elephant shrew has so far only been found in areas with rocky or stony subsoil on mountain slopes or ridges, a habitat type that occurs here only in a highly fragmented manner. A total of only five locations are currently known where the species has been documented, four of them in the Upper Karoo and one in the Lower Karoo. All locations are at an altitude of over 1300 m above sea level. It is believed that the Karoo cliff elephant shrew is very rare due to its attachment to rocky ground. The only evidence of three living individuals to date was found in the Upper Karoo in 2006; follow-up examinations in 2008 were unsuccessful. Two more animals had already been collected before, in 2001, the remaining 12 known individuals are museum specimens. In the Nama-Karoo, the Cape and Western Cliff elephant shrews also occur, but it is unclear whether the respective areas of distribution are different overlap with that of the Karoo Cliff elephant shrew.
Way of life
Nothing is known about the way of life of the Karoo cliff elephant shrew. Due to the probable specialization in hard ground, there may be similarities in behavior to the Cape or Western Cliff elephant shrew.
Systematics
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Internal systematics of elephants according to Heritage et al. 2020
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The Karoo Cliff elephant shrew is a kind from the genus of elephantulus ( Elephantulus ). This genus occurs relatively rich in forms and currently comprises nine species that are distributed over large parts of southern and eastern Africa . The elephantulus form part of the family of shrews (Macroscelididae) within the same order (Macroscelidea). It is a group of smaller mammals endemic to Africa. Today they are divided into two subfamilies. The Rhynchocyoninae only include the proboscis dogs ( Rhynchocyon ) and are therefore considered monotypical . The elephant dog is not only the largest representative of the elephant, but also the only one that predominantly inhabits densely forested habitats . Opposite them are the Macroscelidinae as the second subfamily, which, in addition to the elephant shrews, also includes the proboscis ( Petrodromus ), the North African elephant shrew ( Petrosaltator ), the Somali elephant shrew ( Galegeeska ) and the species of the genus Macroscelides . All representatives of the Macroscelidinae are adapted to rather drier and more open landscapes up to desert-like regions. According to the results of molecular genetic studies, the two subfamilies separated from each other in the Lower Oligocene about 32.8 million years ago, while the Macroscelidinae split more strongly from the Upper Oligocene about 28.5 million years ago.
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Internal system of elephant shrews according to Smit et al. 2011
The representation here neglects the positions of Petrodromus , Petrosaltator , Galegeeska and Macroscelides , all four of which are currently deeply embedded in Elephantulus , making the genus of elephant shrews paraphyletic . |
According to molecular genetic analyzes, the elephant shrews are to be regarded as paraphyletic , since Petrosaltator , Petrodromus and Macroscelides are currently still deeply embedded in the genus Elephantulus . However, there is a group well supported by the results of the genetic studies, which includes mainly the South and some East African species. Accordingly, the Cape elephant shrew ( Elephantulus edwardii ) and the eastern cliff elephant shrew ( Elephantulus myurus ) are the closest relatives of the Karoo cliff elephant shrew, all three form a common group. Slightly outside this family group are other representatives of southern Africa such as the western cliff elephant shrew ( Elephantulus rupestris ) and the dryland elephant shrew ( Elephantulus intufi ). This current group of species may have its origin in eastern Africa and migrated around 11.5 million years ago at the beginning of the Upper Miocene, during a phase that was characterized by the increasing aridization of the continent, towards the southwest and thus to the current distribution areas. The genetic investigations also showed that the Karoo cliff elephant shrew consists of two subgroups, which, however, cannot be phenotypically differentiated. One group is restricted to the Upper Karoo, the other to the Lower Karoo. Both populations differ in 9.8% of the sequenced mitochondrial genetic material, the distance between both groups together to the closest related species, the Cape elephant shrew, is 13.8%.
discovery
The first indications of an unknown species of elephant shrews resulted from genetic studies of the South African elephant shrews, which were published in 2007.The studies were carried out on 106 individuals, mostly museum specimens, from 28 different sites across the entire range, of which 64 were Cape elephant shrews had been identified. A total of seven individuals from the central areas of the Karoo differed significantly from the Cape elephant shrew and were therefore addressed as an independent Karoo clade . Using ten other specimens, three of which were caught alive in 2006 near Calvinia in the Northern Cape Province, and two more were from catches made in 2001 and had reached the California Academy of Sciences , subsequent analyzes were able to confirm the independence of the new species. The first scientific description of the Karoo cliff elephant shrew then took place in 2008 by Hanneline Adri Smit . The holotype (specimen number MMK / M / 7305) includes a fully grown female animal that is one of the three wild-caught animals from the Vonderlingsfontein farm near Calvinia. It is kept in the McGregor Museum in Kimberley , the farm also represents the type locality. All other 16 known individuals are considered to be paratypes . The species name pilicaudus is made up of the Latin words pilus ("hair") and caudus ("tail") and refers to the tuft-like tail tip.
Threat and protection
There are currently no known known major threats to the Karoo Cliff elephant shrew. The occurrence, which is limited to stony terrain, limits the overlap with agricultural areas and pastures. However, since too little information is available about the species, the IUCN currently lists the species as "insufficient data basis" ( data deficient ). Further research into the frequency and exact distribution of the Karoo cliff elephant shrew is necessary. In addition, it is unclear whether the species occurs in other protected areas besides the Karoo National Park .
literature
- Stephen Heritage: Macroscelididae (Sengis). In: Don E. Wilson and Russell A. Mittermeier (eds.): Handbook of the Mammals of the World. Volume 8: Insectivores, Sloths and Colugos. Lynx Edicions, Barcelona 2018, pp. 206-234 (p. 234) ISBN 978-84-16728-08-4
- Hanneline Adri Smit, Terence J. Robinson, Johan Watson and Bettine Jansen van Vuuren: A New Species of Elephant-shrew (Afrotheria: Macroscelidea: Elephantulus) from South Africa. Journal of Mammalogy 89 (5), 2008, pp. 1257-1268
Individual evidence
- ↑ a b c d e f Hanneline Adri Smit, Terence J. Robinson, Johan Watson and Bettine Jansen van Vuuren: A New Species of Elephant-shrew (Afrotheria: Macroscelidea: Elephantulus) from South Africa. Journal of Mammalogy 89 (5), 2008, pp. 1257-1268
- ↑ a b c d Stephen Heritage: Macroscelididae (Sengis). In: Don E. Wilson and Russell A. Mittermeier (eds.): Handbook of the Mammals of the World. Volume 8: Insectivores, Sloths and Colugos. Lynx Edicions, Barcelona 2018, pp. 206-234 (p. 231) ISBN 978-84-16728-08-4
- ↑ a b c Hanneline Adri Smit-Robinson and Galen B. Rathbun: Elephantulus pilicaudus. The IUCN Red List of Threatened Species. Version 2014.3. ( [1] ); last accessed on February 2, 2015
- ↑ a b Steven Heritage, Houssein Rayaleh, Djama G. Awaleh and Galen B. Rathbun: New records of a lost species and a geographic range expansion for sengis in the Horn of Africa. PeerJ 8, 2020, p. E9652, doi: 10.7717 / peerj.9652
- ↑ a b c Hanneline Adri Smit, Bettine Jansen van Vuuren, PCM O'Brien, M. Ferguson-Smith, F. Yang and Terence J. Robinson: Phylogenetic relationships of elephant-shrews (Afrotheria, Macroscelididae). Journal of Zoology 284, 2011, pp. 133-143
- ^ Mike Perrin and Galen B. Rathbun: Order Macroscelidea - Sengis (Elephant-shrews). In: Jonathan Kingdon, David Happold, Michael Hoffmann, Thomas Butynski, Meredith Happold and Jan Kalina (eds.): Mammals of Africa Volume I. Introductory Chapters and Afrotheria. Bloomsbury, London, 2013, pp. 258-260
- ↑ a b Hanneline Adri Smit, Terence J. Robinson and Bettine Jansen van Vuuren: Coalescence methods reveal the impact of vicariance on the spatial genetic structure of Elephantulus edwardii (Afrotheria, macroscelidea). Molecular Ecology 16, 2007, pp. 2680-2692
Web links
- Elephantulus pilicaudus in the endangered Red List species the IUCN 2008. Posted by: Smit-Robinson & Rathbun, 2008. Accessed February 2, 2015.