Cape gold mole

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Cape gold mole
Chrysochloris asiatica Cape golden mole adult IMG 7120.jpg

Cape gold mole rat ( Chrysochloris asiatica )

Systematics
Superordinate : Afrotheria
without rank: Afroinsectiphilia
Order : Tenrecus (Afrosoricida)
Family : Gold mole (Chrysochloridae)
Genre : Cape gold mole ( Chrysochloris )
Type : Cape gold mole
Scientific name
Chrysochloris asiatica
( Linnaeus , 1756)

The Cape gold mole ( Chrysochloris asiatica ) is a small species of the gold mole . It is endemic to southwest Africa , where it inhabits a relatively large area, which mainly includes the rather dry landscapes of the Karoo and the Fynbos . The animals are comparatively widespread and prefer sandy habitats , but have also settled in cultural landscapes such as gardens and parks. Their spindle-shaped body, which lacks externally visible ears and a tail, and their strong forelegs with large digging claws enable them to dig well in the ground. There they create tunnel systems close to the surface, but also spend a certain part of their activities on the surface of the earth. They are nocturnal, solitary, and feed on invertebrates . Reproduction probably takes place during the humid parts of the year. In general, the way of life of the Cape golden mole can be seen as little researched. The species was scientifically introduced by Linnaeus in 1758 , so it is the first named representative of the golden mole. Due to its varied coat color and certain size variations, numerous sub- and synonym species have been described in the course of research history . The stock is not considered to be threatened.

features

Habitus

The Cape gold mole is a small representative of the gold mole with a strong morphological variability. The head-torso length ranges from 9.4 to 11.5 cm, the information on body weight is 34 to 60 g. A conspicuous sexual dimorphism has not been found so far, but males are on average slightly larger than females. Like all gold mole, the Cape gold mole is characterized by a spindle-shaped body, ears and tail are not externally visible. The back fur has a diverse color scheme, ranging from blackish to slate gray or brown-gray to olive gray or silvery brown. The underside is mostly a little lighter in color, blackish, pale creamy gray or grayish white colors predominate. The single hairs here are often paler on the chest and grayer on the stomach. The undercoat is dense and tinted slate gray. Sometimes albinism also occurs, the corresponding individuals appear light or golden brown. The face and chin are accentuated by strikingly light, creamy yellowish markings, which are often mixed with whitish hair. The spots lighten further towards the cheeks, the eyes, which are hidden under the fur, stand out with whitish spots of color. The leathery nose pad is 9 to 10 mm wide and has blunt but distinct corners. The limbs have a characteristically strong structure, they end in four rays at the front and five at the back. Strong claws have formed on the forefoot. The claw of the central ray (ray III) reaches the largest dimensions with a length of 10 to 12 mm and a basal width of 3.5 to 4.6 mm, as with all gold mullets. The two inner rays (rays I and II) have shorter claws that are 5.5 to 7.2 mm (II) and 3 to 4.5 mm (I) long. In contrast, the claw of the outer ray (ray IV) is greatly reduced in length and is hardly visible. The rear foot length is 9 to 14 mm.

Skull and dentition features

The skull measures 21.1 to 25.4 mm in length and 16.1 to 19.2 mm in width. This makes it appear very short and wide, the largest skull width corresponds to about 70 to 78% of the largest skull length. The rostrum is comparatively narrower, the palate width is 30 to 32% of the largest skull length. A particular characteristic can be found in the markedly elongated and thus club-like shaped head of the hammer in the middle ear . With a length-to-width ratio of 3: 1, this is narrower than that of the closely related Visagies Goldmull ( Chrysochloris visagiei ), whose length is twice the width. The hammer head is located in a bony bladder that bulges outwardly at the temporal fossa . Due to the enlargement of the hammer, the entire ear bone can reach a weight of up to 20 mg. The dentition consists of 40 teeth, the dental formula is: . The rearmost molar is usually present, exceptions are some animals from Namaqualand . It can be designed like a nail or, like the anterior molars, have a tricuspid chewing surface pattern; the feature is different depending on the degree of chewing. A talonid does not occur on the lower molars, in contrast to the also closely related Stuhlmann's gold mole ( Chrysochloris stuhlmanni ). The entire upper row of teeth from the canine to the last molar is 5.4 to 6.7 mm long.

distribution

Distribution area (brown) of the Cape Goldmull

The Cape gold mole rat is endemic to southwest Africa . Its occurrence extends from the Cape Peninsula in the South African province of Western Cape eastwards over the Cape Flats to Swellendam in the same province and northwards along the Atlantic coast to Port Nolloth in the Northern Cape Province . Inland, the species has been identified around Ceres , Worcester and Stellenbosch in the south and around Calvinia , Garies and Kamieskroon in the north. The entire distribution area extends over an area of ​​82,000 km². It is located in the south-western dry zone of Africa, but the animals are not found in the very dry areas of the Karoo . The alleged evidence of an individual of the Cape gold mole in the northern Damaraland in Namibia is probably a wrong determination of the find location. The species prefers sandy habitats with different types of vegetation. It is often found in the fynbos , in the Succulent Karoo and in the Renosterveld . It also penetrates cultural landscapes such as gardens, parks, wine-growing areas or lawns. In contrast, it is found less often in rocky areas, although individual populations have also developed mountain plateaus. The population density can be quite high in favorable habitats and is then up to four individuals per hectare . In Stellenbosch, the Cape Golden Mole appears sympatric with the Fynbos Golden Mole ( Amblysomus corriae ), but prefers drier landscapes.

Way of life

Territorial behavior

The way of life of the Cape gold mole has been little studied. He digs shallow tunnels that start from bushes or stone accumulations, where there is usually a nest, and lead outwards. Occasionally he digs deeper tunnels, these are then highlighted by an ejection mound at the entrance. In Namaqualand it has been observed that the animals also penetrate the ejecta mounds of beach graves . In general, the Cape Golden Mole lives solitary with the exception of dams with offspring. When two individuals occasionally meet in the underground, the animals emit chirp sounds with basic frequencies around 2.2  kHz and withdraw. In some cases, such encounters are also associated with mutual biting.

The animals are nocturnal, the intensity of the activities often increases after rainfall. They also cover part of their nightly forays on the surface. In the dry summer months, however, they are rarely found on the earth's surface. The average body temperature of the Cape gold mole is 32.9 ° C with moderate outside temperatures of 28 to 32 ° C, which roughly corresponds to the thermo-neutral zone. It is therefore comparatively low; it only rises to over 36 ° C at higher outside temperatures of 32 ° C. The low body temperature in the normal range is accompanied by a likewise reduced metabolic rate in the resting state, which is only around 68% of the value for insectivores of the same size. Both of these reduce the risk of overheating during increased activities in the narrow tunnel systems, which is advantageous, for example, during the dry summer months when there is less food available. When the ambient temperature drops, the metabolic rate increases four-fold. From about 9 ° C outside temperature, torpor can occur, in which the metabolism drops again to a fifth.

nutrition

Cape Goldmull feeds insect- and carnivorous, the diet consists mainly of worms , woodlice , hundred- and centipedes and insect larvae , including, among others, those of black beetles . According to reports, the animals go to beaches to catch amphipods or woodlice , which often sit on rotting seaweed .

Reproduction

As with most gold molluscs, little is known about their reproductive behavior. Young animals have so far been observed mainly in the months of June to August, which suggests a birth rate in the wetter season. A litter consists of one to three young animals. The newborns are born as nestlings and are almost naked. One cub examined was 47 mm long and had a 16 mm long head. The offspring stay with the mother for two to three months and are suckled. The individual development seems to be quite slow. The boys are very active and make grunting noises. It is noteworthy that the teeth only erupt shortly before reaching the adult stage.

Predators and parasites

Residues of Cape Goldmulls are often in Gewöllen the barn owl detected, suggesting a corresponding surface activities of Goldmullart. No information is available on parasites and diseases.

Systematics

Internal systematics of the gold mole according to Asher et al. 2010
 Chrysochloridae  




 Eremitalpa granti


   

 Huetia leucorhina


   

 Cryptochloris wintoni


   

 Chrysochloris asiatica


   

 Chrysochloris stuhlmanni






   

 Chrysospalax trevelyani


   

 Chrysospalax villosus




   

 Calcochloris obtusirostris



   

 Chlorotalpa duthieae


   

 Chlorotalpa sclateri



   


 Carpitalpa arendsi


   

 Neamblysomus gunningi


   

 Neamblysomus julianae




   

 Amblysomus corriae


   

 Amblysomus hottentotus


   

 Amblysomus marleyi


   

 Amblysomus robustus


   

 Amblysomus septentrionalis


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The Cape gold mole is a species from the genus of the Cape gold mole ( Crysochloris ). Within the genus, chairman's gold mole ( Crysochloris stuhlmanni ) and Visagie's gold mole ( Crysochloris visagiei ) are currently two other species. The chrysochloris in turn form part of the family of the golden moles (Chrysochloridae) which smaller, ground grave mammals from the superiority of the Afrotheria includes. The golden mole are endemic in Africa , the greater part of the representatives are located in the southern part of the continent. Only a few species also inhabit the eastern or central part. Due to their subterranean way of life, they represent habitat specialists , whose habitat is mostly narrowly defined. Two ecological groups can be distinguished within the family. A group consists of the inhabitants of dry to some semi-desert-like landscapes example of Grant's golden mole ( Eremitalpa ), some representatives of the chrysochloris ( Chrysochloris ), such as the Cape Goldmull and the members of cryptochloris . The other group consists of the types of the open grass and savannah landscapes as well as the forests, including the copper gold mole ( Amblysomus ), Arends' gold mole ( Carpitalpa arendsi ) or the representatives of the genera Neamblysomus and Chlorotalpa . There is currently no complete agreement on the internal structure of the gold mole. The construction of the hammer in the middle ear advocates two or three subfamilies: 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 researchers, the latter two form only a single subfamily, the Chrysochlorinae. This anatomically based subdivision of the gold mole partially contradicts the results of molecular genetic studies. Referring to the Cape Gold Mulle, Cryptochloris is the closest relative, which is supported both skeletal anatomically and genetically. The representatives of both genera are characterized by a club-like elongated head of the malleus, which is extraordinarily long in Crysochloris , but not quite as distinct in Cryptochloris .

Carl von Linné

What is noticeable is the strong size and color variation of the Cape Gold Mole. Individuals from the Cape Peninsula are larger and darker, the body fur shows a blackish gray color, which is partially interspersed with a dark brown. In contrast, animals from the Namaqualand have a smaller body stature and a lighter coat that fades from south to north, so that the tint ranges from olive brown to light brown to silvery brown. In addition to the external features, there is also a clear variation in the skeletal anatomy, such as the shape of the head of the hammer in the middle ear . In the past, the great variability of the Cape gold mole led to the establishment of numerous sub-or synonym types . Robert Broom , among others, created C. namaquensis and C. tenuis, two shapes from Garies in Namaqualand in 1907 , which differ only in the relative width of the skull. Twelve years later Austin Roberts followed with C. minor von Klaver on the Olifants River in the South African province of Western Cape, while Oscar de Beaux named C. bayoni from Robben Island near Cape Town in 1921 . The form C. concolor was written by Guy Chester Shortridge and Donald Carter in 1938 and had previously been collected west of Nieuwoudtville near Calvinia in the Northern Cape Province. In 1946 alone, Broom introduced three other representatives, C. dixoni , C. elegans and C. shorlridgei , whose occurrence was limited to individual sites in Namaqualand. There are differences between the three forms in individual color variations and deviations in the hand skeleton as well as in the design of the head of the malleus. They joined in 1950 with C. a. laylori and C. a. visserae two more by the same author, whose origin is given as Lamberts Bay or Eendekuil . Here, too, both forms show individual differences in the construction of the hand and the hammer head. William Ogilby had already described C. damarensis from Damaraland in Namibia in 1838, but the exact origin of the type material is unclear; it may come from the Namaqualand to the south. The varying coat colors and body sizes are explained today with a clinical adaptation to the environment and less with the existence of numerous subspecies. Clear color differences within individual populations also suggest that even local populations show a higher degree of variability. In addition, there is a need to investigate whether individual populations may represent separate species. The distribution area of ​​the Cape golden mole is in the area of ​​the western Cape fold belt , the mountainous elevations of which act as a natural barrier between the individual localities and could thus prevent greater gene flow .

The first scientific description of the Cape Golden Mole was in 1756 by Linnaeus in his Systema Naturae, which is important for biological taxonomy . He named the species Talpa asiatica and added it to the Eurasian moles . As the home of the Cape Goldmulls suspected Linnaeus "Sibiria" where he the key data from the published work in 1734 Thesaurus of Albertus Seba had taken. Today the type locality is generally indicated with the Cape of Good Hope .

Threat and protection

The habitat of the Cape gold mole has undergone dramatic changes over the past 350 years, due to the expansion of human settlements and the intensification of agriculture, and more recently the development of the coastal region for tourism and the near-surface diamond mining have been added. Despite this serious overprinting, the species is still relatively widespread. Thanks to her ability to adapt to cultural landscapes, she was able to develop new living spaces. Individual animals are shot locally by stray dogs and cats , but probably not eaten because of the tough skin and the musky- smelling secretion of their large anus glands . They are also unpopular with gardeners and landscapers because their near-surface tunnels destroy plants. The IUCN lists the Cape Gold Mole as " Least Concern " due to the lack of major threats . It is present in numerous protected areas.

literature

  • Gary N. Bronner: Chrysochloris asiatica Cape 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. 242-244
  • Gary N. Bronner and Nigel C. Bennett: Chrysochloris asiatica (Linnaeus 1758) - Cape golden mole. In: John D. Skinner and Christian T. Chimimba (Eds.): The Mammals of the Southern African Subregion. Cambridge University Press, 2005, pp. 6-7
  • 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. 201) ISBN 978-84-16728-08-4

Individual evidence

  1. ↑ a b c d e f g h i j k l Gary N. Bronner: Chrysochloris asiatica Cape 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. 242-244
  2. ↑ a b c d e f g h i j k l Gary N. Bronner and Nigel C. Bennett: Chrysochloris asiatica (Linnaeus 1758) - Cape golden mole. In: John D. Skinner and Christian T. Chimimba (Eds.): The Mammals of the Southern African Subregion. Cambridge University Press, 2005, pp. 6-7
  3. ^ A b c N. C. Bennett and AC Spinks: Thermoregulation and metabolism in the Cape golden mole (Insectivora: Chrysochloris asiatica). Journal of Zoology 76, 1995, pp. 957-971
  4. ^ A b c d e f 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. 201) ISBN 978-84-16728-08-4
  5. ↑ Matthew J. Mason, Sarah J. Lucas, Erica R. Wise, Robin S. Stein and Melinda J. Duer: Ossicular density in golden moles (Chrysochloridae). Journal of Comparative Physiology A 192, 2006, pp. 1349-1357
  6. ^ A b c d Gary N. Bronner: Chrysochloris asiatica. The IUCN Red List of Threatened Species 2015. e.T40600A21288387. ( [1] ); last accessed on April 1, 2016
  7. ↑ a b c Guy Chester Shortridge: Field notes on the first and second expeditions of the Cape Museum 'Mammal survey of the Cape Province; and descriptions of some new subgenera and subspecies. Annals of the South African Museum 36, 1942, pp. 27-100 ( [2] )
  8. ↑ UB Willi, GN Bronner and PM Narins: Ossicular differentiation of airborne and seismic stimuli in the Cape golden mole (Chrysochloris asiatica). Journal of Comparative Physiology A 192, 2006, pp. 267-277
  9. ↑ 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
  10. ^ A b Robert Broom: A contribution to the knowledge of the cape golden moles. Transactions of the South African Philosophical Society 18, 1907, pp. 283-311 ( [3] )
  11. ^ A b 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
  12. ^ 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
  13. ^ 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
  14. ↑ a b Robert Broom: Some new and some rare Golden moles. Annals of the Transvaal Museum 20, 1946, pp. 329-335
  15. ^ A b Robert Broom: Some further advances in our knowledge of the Cape golden moles. Annals of the Transvaal Museum 21, 1950, pp. 234-241
  16. ^ Robert Broom: On some new species of Chrysochloris. The Annals and magazine of natural history 7 (19), 1907, pp. 262–268 ( [4] )
  17. ^ Austin Roberts: Description of some new mammals. Annals of the Transvaal Museum 6, 1919, pp. 112-115
  18. ↑ Oscar de Beaux: Una nuova crisocloride della Colonia del Capo. Atti della Societa italiana di scienze naturali e del Museo civile di storia Naturale, Milano 60, 1921, pp. 230–115 ( [5] )
  19. ↑ Guy Chester Shortridge and Donald Carter: A new genus and new species and subspecies of mammals from Little Namaqualand and the North-West Cape Province; and a new subspecies of Gerbillus paeba from the Eastern Cape Province. Annals of the South African Museum 32, 1938, pp. 281–291 ( [6] )
  20. ^ William Ogilby: On a collection of Mammalia procured by Captain Alexander during his journey into the country of the Damaras on the south-west coast of Africa. Proceedings of the Zoological Society 1838, p. 5 ( [7] )
  21. ^ Jurgens AJ Meester, IL Rautenbach, NJ Dippenaar and CM Baker: Classification of Southern African Mammals. Transvaal Museum, Pretoria, South Africa, 1986, pp. 15-24
  22. ^ Carl von Linné: Systema naturae. 10th edition, 1758, volume 1, p. 53 ( [8] )
  23. ↑ Oldfield Thomas: On the probable identity of certain specimens, formerly in the Lidth de Jeude Collection, and now in the British Museum, with those figured by Albert Seba in his 'Thesaurus' of 1734. Proceedings of the Zoological Society 1892, p. 309-318 ( [9] )

Web links

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