Hottentot gold mole

Hottentot gold mole
Systematics
Superordinate : Afrotheria without rank: Afroinsectiphilia Order : Tenrecus (Afrosoricida) Family : Gold mole (Chrysochloridae) Genre : Copper gold mole ( Amblysomus ) Type : Hottentot gold mole
Scientific name
Amblysomus hottentotus
( A. Smith , 1829)

The Hottentot gold mole ( Amblysomus hottentotus ) is a type of gold mole . It occurs in southern Africa , its known range is the largest of the representatives of the copper gold mole . Several subspecies are distinguished within the species, which, however, according to genetic studies, can also represent cryptic species . The animals are - like the other golden mulle - characterized by a conspicuously spindle-shaped body with externally invisible ears and tail, as well as by the strong claws of the front feet. Compared to the other copper gold mole, the Hottentot gold mole has a high intraspecific variability. Its preferred inhabited habitats consist of open grass and closed forest landscapes in high and low altitudes, but it also tolerates certain overprinting by humans. The animals live solitary and underground in extensive tunnel systems, which they defend territorially and aggressively. The main food is mainly invertebrates that are sought in the underground. Reproduction takes place all year round. Overall, the way of life of the Hottentot gold mole compared to the other members of the copper gold mole has been studied relatively well. The scientific introduction of the species dates back to 1829. The stock is classified as not threatened.

features

Habitus

The Hottentot gold mole is one of the medium to large representatives of the gold mole . According to a study of 41 individuals, the head-torso length varies from 10.4 to 13.5 cm, the weight ranges from 37 to 85 g. A sexual dimorphism is pronounced, males are on average slightly larger than females. As with the other Goldmullen, the body is also spindle-shaped and has no externally visible ears or tail. The fur on the back can be colored from chestnut brown with a reddish tinge to brownish-black to reddish-black. On the sides of the body, the color of the fur changes into a reddish brown. The underside is mostly tinted light brown, reddish brown or cloudy orange. Sometimes a dark brown line runs in the middle from the throat to the stomach. The intensity of the red tint of the fur is very different in the individual populations . However, albinos that are cinnamon-brown or pale yellow on the back and stomach also occur rarely . The face is generally lighter in color than the back. On each of the cheeks there are a number of yellow-brown-whitish or yellow-orange spots that reach up to the level of the eyes hidden under the skin, but are united behind the fleshy nose. The limbs are short and strong. The hands have four rays, the feet have five rays, each with claws. The central claw (ray III) of the hand is particularly characteristic due to its massive structure. This has a base width of 4.3 to 6.6 mm and a total length of 13 to 16 mm. The claw of the second finger is significantly shorter at 6 to 8 mm, that of the first is only half as long as this. There is only a stunted or button-like claw on the fourth finger. The hind foot shows a blackish or yellowish to reddish brown tint above. Its length varies from 12 to 19 mm.

Skull and dentition features

The greatest length of the skull is 24.6 to 27.7 mm, the greatest width 15.1 to 19 mm. The externally known sexual dimorphism is also found in the skull dimensions, but is less clearly developed there. Compared to the fynbos gold mole rat ( Amblysomus corriae ), the skull is slightly wider and shorter, so that the width of the skull takes up over 61% of the length. As a result, the palatal bone also has relatively smaller dimensions. The bit comprises a total of 36 teeth, the dental formula is: . The molars are characterized by three small cusps on the chewing surface ( tricuspid ). Less than 2% of the animals examined have a third molar, the shape of which is different for each half of the jaw. It is usually only small in size and can either be shaped like a nail or resemble the other rear molars, but this depends on the degree of chewing. The talonid of the lower molars is well developed with the exception of one subspecies ( A. h. Meesteri ). The anterior premolar is characterized by a two-humped shape ( bicuspid or sectorial ), again with the exception of A. h. meesteri , in which the tooth looks more like a molar. The length of the upper row of teeth from the canine to the second molar is 6 to 7.2 mm. ${\displaystyle {\frac {3.1.3.2}{3.1.3.2}}}$

distribution

Distribution area (green) of the Hottentot gold mole

The Hottentot gold mole is endemic to southern Africa . It occurs mainly in the South African provinces of Eastern Cape , KwaZulu-Natal and in the south of Mpumalanga . A single record in the 1990s from the north-west of Lesotho later turned out to be a misidentified specimen of Sclater's gold mole ( Chlorotalpa sclateri ), but an occurrence of the Hottentot gold mole in the far north of Lesotho cannot be ruled out. The distribution area extends over an area of ​​around 280,000 km² and mainly includes the regions of the coastal forests and partly of the Highveld , but also affects the Fynbos and the Karoo in the south . The species inhabits a multitude of landscape types, ranging from open grasslands to closed wooded areas to marshland areas and including mountain regions up to an altitude of 3300 m as well as lowlands. The animals can often be observed in moist soils near rivers and dams, but they can also be found in areas remote from water, provided the subsoil is loose and not too rocky. Some of them also occur in gardens, on golf courses and in other cultural landscapes. The population density in beneficial habitats can be up to 25 individuals per hectare .

Way of life

Territorial behavior

In terms of lifestyle, the Hottentot gold mole is the best-studied representative of the copper gold mole. He lives solitary and underground in buildings and tunnels he has dug himself. The animals dig with their strong front claws, the rear legs are pressed into the wall or push the loose soil to one side. You can change position and direction with a somersault-like twist, the loose material is then pushed into side aisles or to the surface with the help of the muscular head and shoulders. This creates piles of earth that are sometimes clearly visible on the surface next to the entrances. Two different forms of building are known. On the one hand there are tunnels directly under the surface, which are used to search for food, on the other hand deeper tunnels, which extend about 10 to 50 cm below the earth's surface and are used for retreat. The individual tunnels have a diameter of 4 to 6 cm, depending on the size of an individual. They form complex corridor systems that, according to studies in Umdoni Park, can be between 9.5 and 240 m long. The daily increase in length of the corridors is around 4 to 12.4 m for the ones close to the surface and up to 9 m for the deeper ones, it depends on the nature of the subsoil. In the deeper corridors, individual round chambers with a diameter of 15 to 20 cm are embedded, which contain a nest of leaves and grasses that is used as a resting place and retreat. In addition, there are two or three loopholes or escape chambers that extend up to 94 cm deep and to which spiral passages lead.

The animals defend their respective tunnel system actively and aggressively against intruders, which speaks for a pronounced territorial behavior. The territory defense takes place against representatives of the own sex as well as of the opposite sex and takes place through wrestling matches with the forefeet as well as by biting into the groin area. She is accompanied by high-pitched squeaking noises. However, there is a certain degree of tolerance towards conspecifics when territories overlap. Dominant animals sometimes take over a neighboring passage system and thus expand their own territory. Compared to the herbivorous African gray mullet, the Hottentot gold mole shows no aggressiveness, both may live in the same burrows, which reduces the individual costs when creating the tunnels. In the Drakensberg in the province of KwaZulu-Natal, the underground passages of the Hottentot gold mole partly connect with those of Sloggett's lamellar tooth rat .

The Hottentot gold mole is active both day and night. Phases of high activity, which last an average of 2 hours and 20 minutes, alternate with those of rest lasting 3 to 5 hours. The main phases of the activity are at dusk and around midnight. The degree of activity depends on the ambient temperature of the soil, which fluctuates between 0.8 and 32 ° C per year. Optimal conditions prevail at around 23 to 33 ° C, which roughly corresponds to the thermo-neutral range of the Hottentot gold mole. Studies of animals over a period of 14 days have shown that they are around 30% active during this period. At temperatures below 15 ° C or above 30 ° C, the animals fall into a torpor associated with a drop in body temperature and a decrease in metabolic rate . The torpor can last for several days, in cooler periods the temperature drops to just under 2 ° C above the ambient temperature. The lowest measured body temperature is around 8.6 ° C. According to studies, the periods of rigidity are individually and sometimes opportunistically distributed and not mainly tied to particularly cool periods of the year. During torpor, the animals lose significantly less weight than during a corresponding waking phase. This behavior may be related to cost savings, as a way of life that digs underground is extremely energy-intensive.

nutrition

The Hottentot gold mole feeds carnivorous and insectivorous. Its main diet consists of soil-digging invertebrates . According to studies of stomach contents in KwaZulu-Natal, earthworms predominate with a share of 97%, the rest consists of larvae of scarab beetles , snails , nudibranchs , crickets and spiders as well as fine plant material. It has been observed in captive animals that they could consume up to 90% of their own body weight, but the amount of food consumed in wild animals is strongly dependent on the ambient temperature. The prey is found by touch and vibration rather than smell .

Reproduction

Reproduction occurs all year round, but there is a maximum in summer, which is on average more humid and warmer. Females are therefore polyestrial , males continuously produce sperm . The more balanced climate in the gait systems probably means that the animals remain reproductively active regardless of the season. The mating behavior includes chirping calls, foot trampling and up and down head movements in the male, as well as rasping and squeaking sounds in the female. A litter consists of one to three young animals, the average is 1.9. The newborns are 47 mm long and weigh about 4.5 g. They are born nestled and are hairless. The fur on the back only forms from a head-torso length of 72 mm and a weight of 17 g, the stomach remains naked up to this point. The fur there develops from a body length of around 80 mm and a weight of 27 g. From a weight of 35 to 40 g the young leave the maternal nest.

Predators and parasites

The predators include snakes , owls , the white stork , otters , gorse cats , mongooses and jackals . In addition, individual animals are also captured by domestic dogs and cats , but not eaten. So far, no information is available about parasites .

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

The Hottentot gold mole is a species from the genus of the copper gold mole ( Amblysomus ), which with a total of five members form the most varied group within the family of the gold mole (Chrysochloridae). The golden moles are endemic in Africa is less widespread group bottomless grave forming mammals from the superiority of the Afrotheria . They occur mainly in southern Africa, a few species also inhabit parts of eastern or central Africa. The habitats of each species are outlined closely due to the highly specialized lifestyle with few exceptions. Two ecological groups can be distinguished within the gold mole. One forms comprising dry to partly semi-desert-like regions, such as the Grant's golden mole ( Eremitalpa ) or chrysochloris ( Chrysochloris ). The second group includes inhabitants of open grass and savannah landscapes as well as forests, for example the copper gold mole, the giant gold mulle ( Chrysospalax ) or Arends' gold mole ( Carpitalpa ). The internal structure of the family is more or less unclear. A distinction is often made between two or three subfamilies, with the construction of the hammer in the middle ear serving as a feature: The Amblysominae have a normally built malleus, the Chrysochlorinae has a strongly elongated head, while the malleus is spherical in the Eremitalpinae. Some authors combine the latter two into a subfamily, the Chrysochlorinae. This subdivision of the golden mole, based on differences in skeletal anatomy, has not yet been fully comprehensible through genetic findings. According to molecular genetic studies, however, Neamblysomus and Carpitalpa are the closest relatives of Amblysomus .

Within the populations , the Hottentot golden mole shows striking variations in body size and coat pattern. Five subspecies are currently recognized:

• A. h. hottentotus A. Smith , 1829; Eastern Cape from Van Staden's River in the south to the Great Fish River in the north, around the Elandsberge , Winterhoekberge , Suurberge and Winterberge ; in body size intermediate between A. h. longiceps and A. h. iris , the wing bone is narrower than in A. h. pondoliae (less than 28% of the greatest width of the palatine bone ).
• A. h. iris Thomas & Schwann , 1905; Zululand from the Umdloti River northeast to Lake St. Lucia and Cape Vidal ; Dorsal fur darker, reddish black to dark brown with variable reddish brown tint on the sides and on the belly; smallest subspecies with a head-trunk length of 10.7 to 12.5 cm; Claws graceful with a base width of the claw of the third finger less than 5.5 mm, the lower jaw body narrower than in A. h. pondoliae (less than 60% of the width of the palatine bone).
• A. h. longiceps Broom , 1907; in the interior of KwaZulu-Natal from Underberg in the south to Van Reenen in the north, occurs at Harrismith and Clarens also in the Free State ; occasional sightings in Swaziland probably go back to the Highveld Goldmull ( Amblysomus septentrionalis ); largest subspecies with a head-trunk length of 12 to 14.1 cm and thus similar in size to the Highveld and Robust Goldmull ( Amblysomus robustus ), from which it can be distinguished on the basis of skull dimensions; Claws delicate with a base width of the claw of the third finger over 6 mm, the lower jaw body wider than in A. h. pondoliae (over 65% of the width of the palatine bone).
• A. h. meesteri Bronner , 2000; at Graskop and Mariepskop on the Drakensberg mountains south to the White River ; similar in size to A. h. pondoliae , but can be separated from it by the reddish-brown fur color with a reddish-black band of spots on the middle of the back.
• A. h. pondoliae Thomas & Schwann , 1905; from the Great Fish River in the Eastern Cape northwards to the Umdloti River near Durban in KwaZulu-Natal, at the foot of the Drakensberg around Elliot and Maclear , where the subspecies then from A. h. longiceps is detached; second largest subspecies; Lower body about 60 to 64% of the width of the palatine bone.

Internal system of the copper gold mulle according to Mynhardt et al. 2015  Amblysomus    Amblysomus marleyi      Amblysomus ( h. ) Meesteri      Amblysomus corriae      Amblysomus ( h. ) Iris      Amblysomus ( h. ) Natalensis      Amblysomus ( h. ) Pondoliae      Amblysomus hottentotus      Mthatha population      Amblysomus septentrionalis      Amblysomus robustus      Amblysomus ( h. ) Longiceps

Up to the end of the 20th century, the Highveld Goldmull, Marley's Goldmull ( Amblysomus marleyi ) and in parts also the Fynbos Goldmull ( Amblysomus corriae ) were listed as subspecies, while A. h. iris, in turn, was considered an independent species and was called "Zulu Goldmull". It was not until the mid-1990s that genetic and morphometric studies were able to clarify the currently recognized relationships. The Hottentot Gold Mole, the Fynbos Gold Mole and Marley's Gold Mole are characterized by a 30-paired set of chromosomes , but differ significantly in morphometry. The Highveld Goldmull, on the other hand, has 34 and the Robust Goldmull 36 chromosome pairs. Further genetic studies showed that between A. h. meesteri and the other subspecies of the Hottentot gold mole there are differences in the telomer structure of the chromosomes. Accordingly, A. h. meesteri actually represent an independent species. A more recent molecular genetic analysis from 2015 confirmed this, but it also suggests that the other subspecies also represent independent species. In addition, she recognizes A. h. natalensis as a possible further species, which is widespread in the Durban area and described by Austin Roberts in 1946, but so far as a synonym for A. h. pondaliae was conducted. In addition, a previously unnamed population at Mthatha would have to be raised to species status. According to this study, the Hottentot gold mole should not be regarded as monophyletic and thus includes several cryptic species . For the kind of independence at least of A. h. meesteri and A. h. longiceps is also expressed in a preliminary study from 2018. The development of the individual forms goes hand in hand with the dramatic climatic changes during the Pliocene and Pleistocene and the simultaneous emergence of the Great Escarpment and began around 5 to 3 million years ago.

The first scientific description of the Hottentot gold mole was made by Andrew Smith in 1829 under the name Chrysochloris hottentotus . Smith used adult and young individuals from the Interior parts of South Africa ("Inner Areas of South Africa"), with Austin Roberts defining Grahamstown in the Eastern Cape Province as the type locality in 1951 .

Hazard and protection

The Hottentot gold mole is widespread and adaptable to certain changes in the landscape, a decline in the population has not yet been recorded. Larger threats are not known, locally there may be persecution or poisoning by landowners, in some cases animals are also killed by domestic dogs and domestic cats . The IUCN therefore classifies the species as "not threatened" ( least concern ). It is present in several nature reserves.

literature

• Gary N. Bronner and Nigel C. Bennett: Amblysomus hottentotus (A. Smith, 1829) - Hottentot Golden mole. In: John D. Skinner and Christian T. Chimimba (Eds.): The Mammals of the Southern African Subregion. Cambridge University Press, 2005, pp. 18-19
• Gary N. Bronner: Amblysomus hottentotus Hottentot 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. 228-230
• Gary Bronner and Samantha Mynhardt: Amblysomus hottentotus - Hottentot's Golden Mole. The Red List of Mammals of South Africa, Lesotho and Swaziland, 2016 ( [3] )
• 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. 195) ISBN 978-84-16728-08-4

Individual evidence

1. ↑ ^{a b c d e f g h i j k} Gary N. Bronner and Nigel C. Bennett: Amblysomus hottentotus (A. Smith, 1829) - Hottentot Golden mole. In: John D. Skinner and Christian T. Chimimba (Eds.): The Mammals of the Southern African Subregion. Cambridge University Press, 2005, pp. 18-19
2. ↑ ^{a b c d e f g h i j k} Gary N. Bronner: Amblysomus hottentotus Hottentot 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. 228-230
3. ↑ ^{a b c d e f g h} 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. 195) ISBN 978-84-16728-08-4
4. ^ Gary N. Bronner: Non-eographic variation in morphological characteristics of the Hottentot golden mole, Amblysomus hottentotus (Insectivora: Chrysochloridae). Mammalia 60 (4), 1996, pp. 707-727
5. ^ CD Lynch: The mammals of Lesotho. Navorsinge van die Nasionale Museum, Bloemfontein 10 (7), 1994, pp. 177-241
6. ↑ Gary Bronner and Samantha Mynhardt: Amblysomus hottentotus - Hottentot's Golden Mole. The Red List of Mammals of South Africa, Lesotho and Swaziland, 2016
7. ^ ^{A b} Gary N. Bronner and S. Mynhardt: Amblysomus hottentotus. The IUCN Red List of Threatened Species 2015. e.T41316A21286316 ( [1] ); last accessed on November 8, 2015
8. ↑ ^{a b c d e f g} M. A. Kuyper: The ecology of the golden mole Amblysomus hottentotus. Mammal Review 15 (1), 1985, pp. 3-11
9. ↑ M. Scantlebury, BG Lovegrove, CR Jackson, NC Bennett and H. Lutermann: Hibernation and non-shivering thermogenesis in the Hottentot golden mole (Amblysomus hottentottus longiceps). Journal of Comparative Physiology B 178, 2008, pp. 887-897
10. ↑ M. Scantlebury, MK Oosthuizen, JR Speakman, CR Jackson and NC Bennett: Seasonal energetics of the Hottentot golden mole at 1500 m altitude. Physiology & Behavior 84, 2005, pp. 739-745
11. ^ S. Schoeman, NC Bennett, M. van der Merwe and AS Schoeman: Aseasonal reproduction in the Hottentot golden mole, Amblysomus hottentotus (Afrosoricida: Chrysochloridae) from KwaZulu-Natal, South Africa. African Zoology 39 (1), 2004, pp. 41-46
12. ^ ^{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
13. ^ 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
14. ^ 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
15. ^ ^{A b} Gary N. Bronner: New species and subspecies of Golden Mole (Chrysochloridae: Amblysomus) from Mpumalanga, South Africa. Mammalia 64 (1), 2000, pp. 41-54
16. ↑ ^{a b c} Samantha Mynhardt, Sarita Maree, Illona Pelser, Nigel C. Bennett, Gary N. Bronner, John W. Wilson and Paulette Bloomer: Phylogeography of a Morphologically Cryptic Golden Mole Assemblage from South-Eastern Africa. PlosONE 10 (12), 2015, p. E0144995 doi : 10.1371 / journal.pone.0144995
17. ^ Gary N. Bronner: Cytogenetic Properties of Nine Species of Golden Moles (Insectivora: Chrysochloridae). Journal of Mammalogy 76 (3), 1995, pp. 957-971
18. ^ Gary N. Bronner: Geographic patterns of morphometric variation in the Hottentot golden mole, Amblysomus hottentotus (Insectivora: Chrysochloridae). A multivariate analysis. Mammalia 60 (4), 1996, pp. 729-751
19. ↑ C. Gilbert, S. Maree and TJ Robinson: Chromosomal evolution and distribution of telomeric repeats in golden moles (Chrysochloridae, Mammalia). Cytogenetic Genome Research 121, 2008, pp. 110-119
20. ^ Gary Bronner: An imminent updated (2017) taxonomy for golden moles. Afrotherian Conservation 14, 2018, pp. 57–59
21. ^ Andrew Smith: Contributions to the Natural History of South Africa. Zoological Journal 4, 1829, pp. 433-444 ( [2] )

Web links

Commons : Hottentot golden mole rat ( Amblysomus hottentotus )  - Collection of images, videos and audio files

• Amblysomus hottentotus in the endangered Red List species the IUCN 2015 Posted by: G. Bronner & S. Mynhardt, 2014. Retrieved on November 8, 2015.