Duthie's gold mole
| Duthie's gold mole | ||||||||||||
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| Chlorotalpa duthieae | ||||||||||||
| ( Broom , 1907) |
Duthie's gold mole ( Chlorotalpa duthieae ) is a species of gold mole . It is endemic to southern Africa , its range extends along a 275 km long, narrow coastal strip in the South African provinces of the Western and Eastern Cape . There the species is distributed over two different subpopulations that colonize forest and garden areas with loamy soils. The physique of Duthie's gold mole is graceful, but like all gold mole he has a spindle-shaped body that has no externally visible ears or a tail, and strong grave claws on the front feet. It is thus well adapted to an underground, burrowing way of life, but little data is available on its exact behavior. The species was scientifically introduced in 1907. The stock is considered threatened.
features
Habitus
Duthies gold mole is a small representative of the gold mole with a graceful build and slender grave claws on the forefoot. The head-torso length is 9.5 to 13.0 cm, the weight varies between 20 and 41 g. The characteristic spindle-shaped body lacks externally visible ears and the tail, as with all gold molluscs. The back fur has a uniform reddish-black to brownish-black color, the belly and throat are dark gray. The muzzle and forehead appear a little lighter than the back, yellowish patches of color of triangular shape appear on the eyes hidden under the fur. The individual hairs are 8 to 9 mm long. They are colored light gray at the base and dark gray just below the tip. The entire undercoat has a slate gray color. A leather-like padding is formed on the muzzle, which looks comparatively narrow and only measures 1.5 mm in width, the outer sides are rounded. The lips of Duthies Goldmull are whitish in color. The short and strong limbs end in four rays at the front and five at the back. Especially the claws of the front feet are strong and suitable for digging. The claw of the middle (third) ray is largest with a length of 7 to 9 mm and a basal width of 3.5 to 4.0 mm. On the second finger beam, the 4.5 mm claw is only half as long, that of the first finger is 1.5 mm. On the fourth finger there is only a clearly reduced claw 0.7 mm in length. The rear foot length is 9 to 13 mm.
Skull and dentition features
The greatest skull length varies between 22.0 and 24.5 mm, the width between 13.7 and 15.8 mm. The skull is narrow compared to that of its close relative Sclater Goldmull ( Chlorotalpa sclateri ) - both in the area of the cranium as well as the rostrum and the eyes. The width at the front end of the rostrum is 4.0 mm, the palate is 6.8 mm wide, which also corresponds to the width of the skull at the eyes. Male animals can be metrically differentiated from females on the basis of the larger average skull dimensions. The dentition consists of 40 teeth with the following dental formula together: . The anterior lower premolar has a tricuspid chewing surface pattern and thus corresponds to the molars . One of the cusps is missing from the first upper premolar. A distinct talonid appears on the lower molars. The last molar is generally very small, but resembles the other molars. The length of the upper row of teeth from the canine to the last molar is 6.5 to 7.7 mm.
distribution
Duthie's gold mole is endemic to southern Africa . The distribution area extends as a narrow strip along the south coast of George in the South African province of Western Cape east to Port Elizabeth in the province of Eastern Cape, 275 km away . Within their area of distribution, the type of a total of nine localities is known, which can be assigned to two subpopulations: a western one in the area of the Garden Route National Park around Knysna , Wilderness and Tsitsikamma with six sites and an eastern one around Port Elizabeth with three. The nine localities are spread over an area of 14,000 km², but the actual occurrence is limited to only 144 km². The animals inhabit the South African mountain and coastal forests of the fynbos , which thrive on sandy alluvial soils or sandy-loamy subsoil. In the east they penetrate marginally into savannah landscapes . In the region occurs sympatric the Fynbos Golden Mole ( Amblysomus corriae ), but he lived more forest edges, while Duthie Goldmull deeper lives in the woods. Especially in the eastern subpopulation, Duthie's gold mole rat has also been found in cultivated areas such as gardens. It can be very common locally, but there is hardly any quantitative data. Up to four individuals per hectare could be caught in some beneficial habitats .
Way of life
The way of life of Duthie's gold mole rat has hardly been studied. The animals live solitary and are nocturnal. They build tunnels and passages that, starting from a nest in tree roots, run radially outwards just below the ground. Food is sought in these tunnels or in leaf waste on the ground. Two of the gastric contents examined contained mainly earthworms , and in another one there were also remains of molluscs . So far only one pregnant female has been observed. She had two fetuses and was caught in November. In the same month, two males with enlarged testicles were caught, suggesting a reproductive phase during the wetter summer. Occasionally, remnants of Duthie's gold gullet appear in the barn owl's ridges , which also indicates occasional occurrences on the earth's surface.
Systematics
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Internal systematics of the gold mole according to Asher et al. 2010
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Duthies gold mole rat is a species from the genus Chlorotalpa , which also includes Sclater's gold mole rat ( Chlorotalpa sclateri ). The genus forms part of the family of the golden mole (Chrysochloridae), which includes small, soil-digging mammals from the parentage of Afrotheria . The golden mole are endemic to Africa with a focus on the southern part of the continent, a few species also occur in the eastern or central part. Their subterranean way of life means that, with a few exceptions , the habitats of the individual species are narrowly defined. However, two ecological groups can be distinguished. One group consists of residents to dry partly semi-desert-like landscapes, the Grant's golden mole ( Eremitalpa ) or chrysochloris ( Chrysochloris ). The second group includes forms that are native to open grass and savannah landscapes as well as forests, for example the copper gold mole ( Amblysomus ), the representatives of the genus Neamblysomus , Arends' gold mole ( Carpitalpa arendsi ) or the chlorotalpa species. The internal structure of the family has not yet been fully clarified. Often two or three subfamilies are differentiated based on the construction of the hammer in the middle ear : the Amblysominae with a normally built malleus, the Chrysochlorinae with a greatly elongated head of the malleus and the Eremitalpinae with a spherically inflated head of the malleus. According to other authors, the latter two form only a single subfamily, the Chrysochlorinae. This subdivision of the gold mole, based on differences in skeletal anatomy, has not yet been fully comprehensible with the aid of molecular genetic results. Accordingly, despite the enlarged malleus , Chlorotalpa has a middle position between a group composed of Amblysomus , Neamblysomus and Carpitalpa ("Amblysominae") and another group consisting of Chrysochloris , Chrysospalax , Cryptochloris and others ("Chrysochlorinae").
No subspecies of Duthie's golden gull are known. The representatives of the western subpopulation in the Garden Route National Park area are significantly larger than those of the eastern. A certain gene flow between the two groups is not assumed, as the area that separates them is characterized by the drier Strandveld . The first scientific description was made by Robert Broom in 1907 under the name Chrysochloris duthieae and thus within the Cape Gold Mulle. The specimen copy, a female animal with a length of 10.5 cm, comes from the region around Knysna and thus from the distribution area of the western subpopulation, the region is considered a type area. The animal was discovered by AV Duthie, a botany professor; In her honor, Broom chose the specific epithet . Due to the dark color of the fur, Broom noticed similarities to the fynbos golden mole , which also occurs at Knysna , but the higher total number of teeth moved him to assign the individual to a new species. The incorporation into the genus Chlorotalpa took place only in 1924 by Austin Roberts , whereby he determined Duthie's gold mole as a type species. In the period that followed, Duthie's gold mole was partially viewed as a subspecies of Sclater's gold mole. However, differences in the color of the fur and in individual features of the chromosomes as well as different habitat preferences show that both species are independent. Molecular genetic analyzes came to a similar conclusion.
Threat and protection
The main threat to the existence of Duthie's gold mole is progressive changes and further fragmentation of the habitat as a result of the expansion of human settlements and infrastructure measures for the tourist development of the region. About 60% of the forests in which the western subpopulation occurs are under protection, including 400 km² under state. As a result, it is only slightly affected by such overprints. In the peripheral areas, however, radical changes can occur due to the conversion of forest areas into plantations or logging. None of the localities of the eastern population are protected, so that the quality of the populated landscapes is rapidly declining. However, the species also occurs more frequently in cultivated areas such as gardens, which indicates that it tolerates moderate changes. Subordinate the capture of individual individuals by domestic dogs and house cats have a local influence, as well as the persecution by gardeners. The entire population is currently classified by the IUCN as "threatened" ( vulnerable ). Major sanctuaries where Duthie's gold mole occurs are the Garden Route National Park and the Keurboomsriver Nature Reserve .
literature
- Gary N. Bronner and Nigel C. Bennett: Chlorotalpa duthieae (Broom, 1907) - Duthies's golden mole. In: John D. Skinner and Christian T. Chimimba (Eds.): The Mammals of the Southern African Subregion. Cambridge University Press, 2005, p. 11
- Gary N. Bronner: Chlorotalpa duthieae Duthie's Golden-mole. 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. 239-240
- William A. Taylor, Samantha Mynhardt and Sarita Maree: Chrysochloridae (Golden moles). 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. 180–203 (p. 200) ISBN 978-84-16728-08-4
Individual evidence
- ^ A b c Robert Broom: A contribution to the knowledge of the cape golden moles. Transactions of the South African Philosophical Society 18, 1907, pp. 283-311 ( [1] )
- ^ A b c d e f Gary N. Bronner and Nigel C. Bennett: Chlorotalpa duthieae (Broom, 1907) - Duthies's golden mole. In: John D. Skinner and Christian T. Chimimba (Eds.): The Mammals of the Southern African Subregion. Cambridge University Press, 2005, p. 11
- ↑ a b c d e Gary N. Bronner: Chlorotalpa duthieae Duthie's Golden-mole. 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. 239-240
- ^ A b c William A. Taylor, Samantha Mynhardt and Sarita Maree: Chrysochloridae (Golden moles). 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. 180–203 (p. 200) ISBN 978-84-16728-08-4
- ^ A b c Gary N. Bronner: Chlorotalpa duthieae. The IUCN Red List of Threatened Species 2015. e.T4768A21285581 ( [2] ); last accessed on December 28, 2015
- ↑ Cassandra Pinheiro, Michaela L. Venter, Lauren Sahd, Gary N. Bronner and Sanet H. Kotzé: Comparative gastrointestinal morphology of seven golden mole species (Mammalia: Chrysochloridae) from South Africa. Journal of Morphology 279, 2018, pp. 1776-1786
- ↑ a b c Robert J. Asher, Sarita Maree, Gary Bronner, Nigel C. Bennett, Paulette Bloomer, Paul Czechowski, Matthias Meyer and Michael Hofreiter: A phylogenetic estimate for golden moles (Mammalia, Afrotheria, Chrysochloridae). MC Evolutionary Biology 10, 2010, p. 69 doi : 10.1186 / 1471-2148-10-69
- ^ A b Alberto M. Simonetta: A new golden mole from Somalia with an appendix on the taxonomy of the family Chrysochloridae (Mammalia, Insectivora). Monitore Zoologico Italiano NS Supplement 2, 1968, pp. 27-55
- ^ Gary N. Bronner: Family Chrysochloridae Golden-moles. 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. 223-225
- ^ Austin Roberts: Some additions to the list of South African mammals. Annals of the Transvaal Museum 10 (2), 1924, pp. 59-76
- ^ Gary N. Bronner: Cytogenetic Properties of Nine Species of Golden Moles (Insectivora: Chrysochloridae). Journal of Mammalogy 76 (3), 1995, pp. 957-971
Web links
- Chlorotalpa duthieae in the Red List of Threatened Species of the IUCN 2014. Posted by: G. Bronner, 2014. Accessed on 31/12/2015.