Giant gold mole

Giant gold mole
Giant gold mole ( Chrysospalax trevelyani ), specimen
Systematics
Superordinate : Afrotheria without rank: Afroinsectiphilia Order : Tenrecus (Afrosoricida) Family : Gold mole (Chrysochloridae) Genre : Giant Gold Mulle ( Chrysospalax ) Type : Giant gold mole
Scientific name
Chrysospalax trevelyani
( Günther , 1875)

The giant gold mole ( Chrysospalax trevelyani ) is a mammal from the family of the gold mole (Chrysochloridae) and is their largest representative. It is endemic to southern Africa and inhabits soft soils in mountain and coastal forests in the South African province of Eastern Cape . The animals are well adapted to an underground way of life with a spindle-shaped body, externally invisible ears and tails as well as strong front limbs that have been transformed into digging tools. They dig short tunnels that are connected by overground paths. Compared to other gold molluscs, the animals spend more time on the earth's surface. Their main food, which they mostly look for at night, consists of invertebrates such as earthworms and millipedes . Little is known about the reproduction of the giant gold mole. The species was scientifically introduced in 1875. The distribution area is severely affected by forest destruction. The giant gold mole can only be found in fewer than a dozen locations there today. Its existence is therefore classified as endangered.

features

Habitus

According to its name, the giant gold mole represents the largest member of the gold mole family. It reaches a head-to-trunk length of 20.8 to 23.5 cm and a weight of 410 to 500 g. A sexual dimorphism is not evidently developed, but this could also be due to the insufficient number of examined individuals. Of about a dozen animals from the Amathole Forest measured , males had an average weight of 535 g, females 438 g. As with the other Goldmullen, the body is characterized by a spindle shape, ears and tail are not externally visible. The fur is relatively coarse, the top hairs are up to 20 mm long on the back, and are shorter on the rest of the body. They have a grayish-yellow base and a dark brown tip with a yellowish tinge. The undercoat is dense and tinted yellowish-brown-gray. The back is dominated by a shiny brown, yellowish brown or greyish brown color. The underside is similarly colored, but mostly a little paler. The head generally appears a little darker than the back. Two yellowish spots of color appear on each of the cheeks in the area of ​​the fur-covered eyes, and another is formed on the ear openings. The throat, chest and the underside of the front legs are marked cloudy yellow. The limbs are generally well built. The hands of the animals have four rays, the feet five, each ray is equipped with a claw. The front limbs in particular have been transformed into powerful digging tools. This is where the middle claw (ray III) becomes strongest with a total length of 17 to 19 mm and a basal width of 7 mm. The claws of the second and first fingers are significantly shorter with 12 and 4 mm in length, respectively, while the fourth finger has only a greatly reduced claw. The entire rear foot measures between 20 and 28 mm in length. The longest claw is formed here on the fourth toe and reaches dimensions of around 10 mm.

Skull and dentition features

The skull becomes 39.9 to 43.2 mm long and 24.2 to 27.4 mm wide. As a result, it is relatively elongated and narrow, the greatest width is 60 to 65% of the greatest length, but it has a broad rostrum , the palate of which is 30 to 35% of the greatest length of the skull. Differences between males and females cannot be identified from skull measurements. Characteristic is the inflated and enlarged head of the hammer in the middle ear , which is located in an externally visible, clearly arched, bony swelling on the temporal fossa . On the completely closed zygomatic arch , there are plates pointing backwards and upwards, which extend over the skull. A pronounced crest serves as a starting point for the extraordinarily strong masticatory muscles . The dentition consists of 40 teeth with the following dental formula together: . The rearmost molar is relatively small, but with its three cusps on the chewing surface ( tricuspid ) resembles the other rear molar teeth. There is a distinct trigonid on the lower molars. The foremost premolar has a sectorial design and is therefore characterized by only two small cusps on the chewing surface. The entire upper row of teeth from the canine to the last molar measures between 9.4 and 10.2 mm. ${\displaystyle {\frac {3.1.3.3}{3.1.3.3}}}$

distribution

Distribution area (green) of the giant gold mole

The giant gold mole is endemic to southern Africa , its range extends along the coast of East London northeast to Port St. Johns and inland to the Amathole and Kologha Mountains near King William's Town and Stutterheim . It is completely located in the South African province of Eastern Cape . The total distribution area amounts to an area of ​​41,600 km². Within this area, however, the species has only been detected at ten locations, the actual occurrence is thus limited to 272 km², the population is therefore highly fragmented. The animals inhabit the afromontane forests and coastal forests of the region, but sometimes penetrate into adjacent open grasslands. They prefer undisturbed, primeval forest areas with soft, well-developed soils and a lot of leaf waste. They avoid steep slopes and rocky areas. The giant gold mole is also not found in landscapes influenced by humans, such as on commercially used plantations. The species can occur locally in relatively high numbers, but quantitative data are not available.

Way of life

Territorial behavior

The way of life of the giant gold mole is generally little researched, but it shows some peculiarities in behavior. Like many other gold mole, it is active at night and at dawn. Its main activities take place between 4:00 p.m. and 8:00 p.m. and between 11:00 p.m. and 1:00 a.m., the phases are interrupted by periods of rest. The strong grave claws enable him to a digging way of life, but the giant gold mole spends more time on the earth's surface than other members of the family. The tunnel systems consist of various shorter corridors from 1.0 to 13.6 m in length. They include chambers, nests near tree roots, and dead ends. According to unconfirmed reports, the above-ground entrances in the Pirie Forest near King Williams Town are characterized by 40 to 60 cm diameter and 25 cm high piles of earth, from which the tunnel led into the ground at a 60 ° incline and then branches off after a short distance. They are also often in the shade of trees. This contradicts the best documented field studies to date that have been carried out in the nearby Amathole Forest . Accordingly, there was no evidence of a pile of earth at 140 documented entrances to the burrows of the giant gold mole, rather they were open and the ejecta was probably used to mark the paths and paths that connect the individual tunnels and corridors above ground in a direct line. These can be recognized by small walls and ripples made of earth and leaf material. According to observations of animals from the same forest area, the predominantly nocturnal activities consist of foraging in leaf waste on the surface of the earth and digging in the earth. One animal covered 256 m within seven nights and passed several other burrows. The longest distance covered in one piece was 128.4 m, but on average it was 36.6 m per night and the respective length of stay at one location was 36 hours. The nocturnal activities of the giant gold mole are probably not a result of the availability of food, rather they minimize the risk of falling prey to predators. As a rule, the animals are very alarmed and seek shelter in the event of minor disturbances. In addition, thermoregulation should also play a certain role in night activity. The average daytime outside temperature in the Amathole Forest is around 23.1 ° C, the temperature in the buildings averages 18.1 ° C, which corresponds to the night temperature on the ground. Activities decrease during the cooler winter months, and torpor can also occur at lower outside temperatures . According to reports, the giant gold mole occasionally also swims, paddling with its forefeet. Its comparatively large and clumsy physique with a small body surface area and few air cushions in the fur make it unlikely that it will be able to cover greater distances in the water. Possibly the giant gold mole represents a more social species within the gold mole. According to reports that have not yet been confirmed, several individuals can spend the winter in a burrow.

nutrition

The giant gold mole looks for food mainly above ground, where it rummages through leaf waste or digs small holes. The areas examined are recognizable as small, meandering paths away from the direct paths. It mainly eats invertebrates , its preferred prey include earthworms , including representatives of the Microchaetus genus . Where these are seldom available, the giant gold mole also feeds on millipedes . This includes, for example, Sphaerotherium from the giant globules group , which occurs relatively frequently in leaf litter; however, the giant gold mole avoids prey animals with an individual weight of more than 1.9 g. Forms such as Doratogonus and Chersastus from the group of pinnipedes are far less on the menu due to the strong smell that the millipedes can give off in danger. It is generally assumed that the animals eat a richer spectrum of food.

Reproduction

During mating, the male mounts the female in a canine-like manner. A pregnant female had two embryos in the uterus . In the only birth observed so far, only one cub was born in October. This was 77 mm long and 28 g heavy and had a rear foot length with claws of 11 mm. It resembled the adult animals, but had relatively shorter claws on the forefoot. The back fur was slate gray and short-haired, became lighter on the sides, while no fur was formed on the stomach. The boy had only poor motor skills, poor thermoregulation and hearing . The mother suckled the young in a lying position and acted protectively. Over the next five days, it gained an average of 3 mm in length and 1 g in weight. During this time the fur became longer, there were spots of color on the face as well as the first vibrissae . The motor skills increased. The newborn also made the first sounds in the form of whimpering, squeaking and gasping. The young left the maternal nest for the first time on the fourth day and covered a distance of 25 cm. On the seventh day, it measured 94 mm in total and had a rear foot length of 14 mm (it died at this point). Overall, development appears to be relatively slow, suggesting an extended phase of parental care.

Parasites

A proven internal parasite of the giant gold mole is the genus Heptamegacanthus from the group of scratch worms .

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

Albert Carl Ludwig Gotthilf Günther

The giant gold mole is a species from the genus of the giant gold mole ( Chrysospalax ). This also contains the wire-haired golden mole rat ( Chrysospalax villosus ) and thus includes the two largest representatives within the golden mole family (Chrysochloridae). The golden mole represent smaller, soil-digging mammals from the parentage of the Afrotheria and are endemic to Africa . Their occurrence has a focus in the southern part of the continent, a few species also inhabit the eastern or central part. Their subterranean way of life means that the individual species, with a few exceptions, form habitat specialists with narrowly defined distribution areas. Two ecological groups can be distinguished within the family. The first group include the residents of dry to partly semi-desert landscapes, as the Grant's golden mole ( Eremitalpa ) or chrysochloris ( Chrysochloris ). In the second group are the forms that are adapted to open grass and savannah landscapes as well as forests, such as the copper gold mole ( Amblysomus ), representatives of the genera Neamblysomus and Calcochloris , Arends' gold mole ( Carpitalpa arendsi ) or the giant gold mulle. There is still no full agreement on the internal structure of the gold mole. Based on the construction of the hammer in the middle ear , two or three subfamilies can be separated from one another: 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. These anatomical outline approach to molecular genetics not fully understand investigations. According to this, Chrysospalax is relatively basal in a group that consists of the genera Calcochloris , Eremitalpa , Chrysochloris , Cryptochloris and others and, with the exception of Calcochloris, would generally correspond to the Chrysochlorinae. From an anatomical point of view, due to the inflated head of the hammer , Chrysospalax should be most closely related to Eremitalpa (and with these form the Eremitalpinae).

Graphic representation of the giant gold mole from the first description by Albert Günther

There are considerable color variations within and between the individual populations of the giant gold mole. Because of this, no subspecies are distinguished.

The species was first scientifically described in 1875 by Albert Günther under the name Chrysochloris trevelyani . The introduction took place with the help of a 24.3 cm long individual from the Pirie Forest near King Williams Town , which is considered the type locality of the giant gold mole. The animal had reached the Natural History Museum in London via Herbert Trevelyan , where Günther was working at the time. Trevelyan himself came into possession of the carcass through local hunters. Günther named the species trevelyani in his honor . Theodore Gill created the generic name Chrysospalax , which is valid today, in 1883, which he distinguished from the other genera known at the time ( Chrysochloris and Amblysomus ) due to the well-developed 40 teeth and the strong plates behind the zygomatic arches . For a short time, in 1892, Edward Drinker Cope referred the giant and wire-haired gold mole rat into the genus Bematiscus, which he had established . He also defined this using the 40 teeth and the distinctive talonid on the lower molars. However, the giant gold mole was returned to Chrysospalax in the following years, the wire-haired gold mole remained in the genus Bematiscus until the 1950s .

Threat and protection

The greatest threat to the existence of the giant gold mole is the destruction of the habitat. This happens in the coastal forests, for example, through the expansion of human settlements such as around East London or through the development of the region for tourism and the construction of the necessary infrastructure. In general, the massive extraction of timber and firewood has a negative impact on natural forests. To a certain extent, overgrazing by livestock also plays a certain role. Hunting by domestic dogs and cats living in the wild can have local effects. Historically, 17 locations with evidence of the giant gold mole are known, currently the number has shrunk to ten. Although some forests in the range of the species are protected, the corresponding protection regulations are rarely enforced on site. Since the Riesengoldmull also does not occur in more than impressed by man-made landscapes and shows so no tolerance to habitat changes, which classifies IUCN him as "high risk" ( endangered one). For effective protection, field investigations into the actual distribution of the species are currently primarily necessary.

literature

• Gary N. Bronner and Nigel C. Bennett: Chrysospalax trevelyani (Günther, 1875) - Giant golden mole. In: John D. Skinner and Christian T. Chimimba (Eds.): The Mammals of the Southern African Subregion. Cambridge University Press, 2005, pp. 3-4
• Gary N. Bronner: Chrysospalax trevelyani Giant 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. 247-248
• AH Maddock: Chrysospalax trevelyani: an unknown and rare mammal endemic to Southern Africa. Cimbebasia 8 (10), 1986, pp. 87-90
• 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. 202) ISBN 978-84-16728-08-4

Individual evidence

1. ^ ^{A b} A. C. Duckworth, AH Maddock and GC Hickman: A live trap for the capture of the giant golden mole. South African Journal of Wildlife Research 17 (1), 1987, pp. 17-19
2. ^ ^{A b} Albert Günther: Description of a new species of Chrysochloris from South Africa. Proceedings of the Zoological Society of London, 1875, pp. 311-312 ( [1] )
3. ↑ ^{a b c d e f g h} Gary N. Bronner: Chrysospalax trevelyani Giant 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. 247-248
4. ↑ ^{a b c d e f g h} Gary N. Bronner and Nigel C. Bennett: Chrysospalax trevelyani (Günther, 1875) - Giant golden mole. In: John D. Skinner and Christian T. Chimimba (Eds.): The Mammals of the Southern African Subregion. Cambridge University Press, 2005, pp. 3-4
5. ^ ^{A b c d e} 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. 202) ISBN 978-84-16728-08-4
6. ^ Albert Günther: Notes on Chrysochloris trevelyani. The annals and magazine of natural history 17, 1876, pp. 346–348 ( [2] )
7. ^ ^{A b} Gary N. Bronner: Chrysospalax Trevelyani. The IUCN Red List of Threatened Species 2015. e.T4828A21289898 ( [3] ); last accessed on February 12, 2016
8. ^ ^{A b} A. H. Maddock and GC Hickman: A preliminary report on locomotory activity in wild and captive Chrysospalax trevelyani (Mammalia: Chrysochloridae), South African. Journal of Zoology 20 (4), 1985, pp. 271-273
9. ↑ ^{a b c d} A. H. Maddock: Chrysospalax trevelyani: an unknown and rare mammal endemic to Southern Africa. Cimbebasia 8 (10), 1986, pp. 87-90
10. ^ W. Poduschka: Notes on the giant golden mole Chrysospalax trevelyani Gunther, 1875 (Mammalia: Insectivora) and its survival chances. Zeitschrift für Mammaliankunde 60, 1980, pp. 1-11
11. ^ AC Duckworth and GC Hickman: Defense strategies in coexisting species of oniscomorph and julimorph millipeds against predation by the giant golden mole (Chrysospalax trevelyani). South African Journal of Science 81, 1985, pp. 700-701
12. ^ Gary N. Bronner: Notes on the early post-natal development of a giant golden mole (Günther, 1875) born in captivity (Mammalia: Insectivora; Chrysochloridae). Koedoe 35 (2), 1992, pp. 57-58
13. ↑ Mary R. Spencer Jones: Heptamegacanthus niekerki ng, n. Sp. (Acanthocephala: Oligacanthorhynchidae) from the south-east African insectivore Chrysospalax trevelyani (Günther, 1875). Systematic Parasitology 15, 1990, pp. 133-140
14. ^ ^{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
15. ^ ^{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
16. ^ 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
17. ^ Robert Broom: A contribution to the knowledge of the cape golden moles. Transactions of the South African Philosophical Society 18, 1907, pp. 283-311 ( [4] )
18. ^ Theodore Gill: Insectivora. In: John Sterling Kingsley (ed.): The standard natural history. Volume 5: Natural history of mammals. Boston, 1883, pp. 134–158 (p. 137) ( [5] )
19. ^ ED Cope: On the Habits and Affinities of the New Australian Mammal, Notoryctes typhlops. The American Naturalist 26 (302), 1892, pp. 121-128

Web links

Commons : Giant gold mole ( Chrysospalax trevelyani )  - Collection of images, videos and audio files

• Chrysospalax trevelyani in the endangered Red List species the IUCN 2014 Posted by: S. Maree, 2014. Accessed on 12/02/2016.