Cape Blessmull
| Cape Blessmull | ||||||||||||
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Cape Blessmull ( Georychus capensis ) |
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| Systematics | ||||||||||||
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| Scientific name of the genus | ||||||||||||
| Georychus | ||||||||||||
| Illiger , 1811 | ||||||||||||
| Scientific name of the species | ||||||||||||
| Georychus capensis | ||||||||||||
| ( Pallas , 1778) |
The Cape Blessmull , Actual Blessmull or Cape Mullratte ( Georychus capensis ) is the only representative of the genus of the Blessmulle ( Georychus ). The range of the animals is limited to South Africa . Like all sand diggers, they live underground and dig duct systems into the ground with the help of their conspicuous incisors. In contrast to the gray mullet and the naked mole rat, they do not live in colonies, but are territorial loners who primarily feed on underground roots and tubers.
features
general characteristics
The Cape Blessmull reaches a head-torso length of 8.5 to 23.1 centimeters for the males and 13.1 to 18.1 centimeters for the females, the weight is about 80 to 270 grams. This makes it a medium to large species within the sand graves. There is only a short tail with a length of about 2 centimeters and the hind foot length is 25 to 30 millimeters. There is no sexual dimorphism .
The body is cylindrical with a flat back. It is colored red-brown to brown on the upper side, the belly side is clearly lighter in color, silvery gray. The fur is thick and woolly. The forehead area and the area below the eyes are dark brown to black, the ears and eyes as well as the pink nose are surrounded by white spots, which form a conspicuous facial drawing and also include the lips. The head is large and blunt with a horseshoe-shaped nose. The teeth are very prominent, the ears only consist of a round opening without auricles. The eyes are small and black with a large white eye ring. The facial whiskers are longer than those of the trunk, and short stiff hairs arise from the mouth, short tail, and the outer edges of the feet. The limbs are short and strong, the feet relatively large with leathery soles. Front paws and hind paws are usually white. The tail is pink with a line of coarse white hairs extending from it.
The male's testicles are located in the abdominal area, the penis is enclosed in a sheath. In females, the vagina is separated from the anus by a Y-shaped dam . They have three pairs of teats , two pairs in the chest area and one in the groin area.
Skull features
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The skull reaches a length of about 38 to 51 millimeters, the width is about 25 to 37 millimeters in the area of the zygomatic arches and 15 to 18 millimeters in the area of the brain skull . It is flattened dorsoventrally and adult animals have pronounced sagittal and neck crests. The zygomatic arch is strongly extended, the infraorbital window is small and rounded. The lower jaw is about 29 to 42 millimeters long. Compared to Bathyergus , the skull is less strongly built.
The animals have a one in the upper jaw and the lower jaw per half incisor tooth trained incisors (incisive) to which a tooth gap ( diastema follows). This is followed by one premolar and three molars . In total, the animals have a set of 20 teeth. The conspicuous incisors are white and, in contrast to those of related species, unnotched, the tooth roots reach behind the pterygoid region and are accordingly rooted behind the molars. In contrast to other sand graves, even as adults they have molar- shaped molars in the upper jaw with an outer and an inner fold; in related species these are present as simple, egg-shaped teeth. The lower jaws are not ankylosed , which allows the tips of the incisors to separate. The Cape Mol rat's incisors grow and wear out continuously as the animals use them to dig.
Genetic traits
The genome consists of a diploid chromosome set of 2n = 54 chromosomes (FN = 104). Although the species is regarded as monotypical, i.e. no subspecies are distinguished, differences in the mitochondrial DNA and allozyme sequences indicate that the populations in the Cape Town area compared to KwaZulu Natal have been separate for a long time or that there are even separate species. The genetic differences in the cytochrome b sequences between the southern and northern populations amount to up to 13.7%.
Differentiation from related species
In the size and weight of Cape mole-rat similar to the partially sympatrically occurring Damara Graumull ( Fukomys damarensis ), but differs therefrom significantly by the pronounced face drawing. In addition, it does not have any feeler hairs on its body, like those found in the Damara-Graumull. The Cape beach grave ( Bathyergus suillus ) is larger than the Cape Blessmull and is clearly different in color. Its fur is cinnamon brown and there is often a dark back band, the conspicuous facial markings are missing and the incisors are clearly notched. The African gray mull ( Cryptomys hottentotus ) is significantly smaller in comparison and also colored differently. The fur is fawn to gray in these.
distribution
The range of the Cape Blessmull is restricted to southern Africa and it occurs only in the Republic of South Africa . It is distributed in parts of the Western Cape and Eastern Cape provinces and in isolated populations in KwaZulu-Natal and Mpumalanga . The distribution is limited to areas with moderately moist soils and mostly with annual rainfall over 500 millimeters, but in some areas, such as Nieuwoudtville , Citrusdal , Moorreesburg and Worcester , this can be lower. The distribution area extends north to Nieuwoudtville in the North Cape Province and east over Port Elizabeth to Bathurst .
Fossil finds suggest that the species had a much wider distribution earlier, which decreased during the Quaternary . The populations in the provinces of Mpumalanga and KwaZulu-Natal could therefore be geographical relics. In southern KwaZulu-Natal along the border to Lesotho and in central Mpumalanga there are several other isolated subpopulations of the species. Overall, its distribution is limited to individual local regions and it is rarely found across the entire range. Regionally, however, it can reach numbers of more than 30 individuals per hectare, especially in the region around Cape Town.
Way of life
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The Cape Blessmull is a rodent that lives primarily underground and digs tunnels, but is rarely found on the surface outside of the burrows. The habitats of the Cape Blessmull are semi-arid zones in South Africa with preferably loose and sandy to loamy soil and rainfall of at least 500 millimeters per year. It is believed that it was originally a habitat specialist who needed areas with loose steppe vegetation in the immediate vicinity of rivers and is mainly found in South African fynbos . Today, however, it is often detected in human-modified and watered environments such as golf courses, gardens or on the main campus of the University of Cape Town .
In contrast to the gray mullet and the naked mole rat, the animals do not live in colonies with several animals, but are territorial loners who mainly feed on underground roots and tubers. They put their burrows close to the surface of the earth. The duct systems are 50 to 130 meters long and have a slightly hypoxic microclimate of 20.4% oxygen , 1.2 to 12% carbon dioxide and a humidity of around 95%. The animals themselves are homeothermal with a body temperature that is evenly regulated to 36 ° Celsius and an ambient temperature of only 12 to 32 ° Celsius in the duct system.
The Cape Blessmull is a territorial loner outside of the mating season, which aggressively defends the boundaries of its territory against conspecifics. Communication with other animals of the same species is done by drumming the hind legs.
Digging
The incisors are worn down when digging in hard ground and thus sharpened, and they grow back continuously. If the jaws are fully open while digging, stiff oral bristles push soil particles aside, preventing them from entering the throat. Two skin flaps behind the incisors prevent soil from penetrating the esophagus and trachea and thus preventing suffocation. The claws of the front paws loosen the soil and shovel it backwards under the animal to be picked up by the rear paws. The soles of the hind feet are leathery and soft with a border of stiff hair on the outer edges. As soon as a pile has gathered behind an animal, he pushes it backwards down the tunnel with his small tail and its fan of stiff hair.
Diet and water intake
Like all sand graves, the Cape Blessmull is herbivorous and its food consists mainly of underground plant parts of geophytes such as roots , bulbs and tubers , only about 6% of the food is above-ground plant parts. The plants that make up the food spectrum include, above all, species of the Hyacinthaceae ( Albuca , Lachenalia and Ornithogalum ), the Iridaceae ( Homeria , Micranthus and Romulea ) and the Oxalidaceae ( Oxalis ). These also include species with ingredients that are toxic to livestock and other herbivores, such as cardiac glycosides , which the Cape Blessmull can absorb without any problems. The animals dig for food in the ground where they dig feed tunnels with a diameter of 7 to 8 centimeters. In specially created storage rooms, the animals also selectively collect larger plant parts of various species, whereby the stores can contain more than 5,000 individual parts. The stored plants are mainly eaten when the females have young or when foraging for food is difficult due to unfavorable conditions and drought with hard soils.
The animals do not consume water, they get all the fluids they need from their food. Geophytes have a high moisture content of 70 to 80%. They usually have a fibrous outer shell that has to be removed when eating. This is done by the animals holding the plant parts between their forefeet and using their feet and teeth to peel off the layers of the shell towards the tip. The digestion of cellulose takes place primarily in the appendix and rectum , where the intestine is colonized by cellulose-digesting endosymbionts such as bacteria, protozoa and fungi ( cecotrophy ). The fecal pills digested in this way are excreted by the animals and reabsorbed through coprophagia in order to use the nutrients and amino acids .
Reproduction and development
The mating and reproduction time of the animals is seasonal and is from August to December. While the animals aggressively defend their territories against conspecifics outside the mating season, their communication behavior changes during the mating season. At the beginning of the mating season, males and females drum at different frequencies and thus signal their readiness to mate. In males, the testosterone level in the blood rises and the testicles and accessory sex glands swell. The drumming by the males becomes extremely fast, each drum impulse lasts about 2 minutes with a single beat length of 0.035 seconds. The drumming can be heard above the ground up to 10 meters from the source. The females do not drum as fast with a beat length of about 0.05 s. Courtship is usually initiated by the male and mating is brief. It consists of several short copulations of two or three thrusts per second, which are interrupted by short periods of time in which they groom and clean themselves and especially their genitals .
The females give birth to a litter of three to ten pups after a gestation period of 44 to 48 days, the average litter size is six pups. The animals are mainly born in the South African summer between August and December, with a single female producing a maximum of two litters per season. The females gain up to about 40% in body weight during the gestation period. The sex ratio of the young when comparing males to females is about 2: 1. The newborns are 3 to 4 inches long and weigh 5 to 12 grams. They are naked and blind at birth, after 7 days the coat develops and shows the typical coat pattern. On the ninth day they open their eyes and from the 17th day they start to eat solid foods in addition to breast milk . After about four weeks the young animals are weaned by the mother and after about 35 days the animals develop their territorial behavior and from the 50th day onwards they leave the maternal den and scatter above or below ground in the environment.
Systematics
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Phylogenetic system of the sand graves and the naked mole rat
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The Cape Blessmull is assigned to the Blessmullen ( Georychus ) as an independent and unique species . The first scientific description comes from Peter Simon Pallas , who in 1778 in his work "Novae species Quadrupedum e Glirium ordine, cum illustrationibus varies complurium ex hoc ordine Animalium" described it as Mus capensis from the Cape of Good Hope in South Africa and assigned it to the mice . In 1811 Johann Karl Wilhelm Illiger described the genus Georychus and classified it together with the Northern Mull-Lemming ( Mus talpinus , today Ellobius talpinus ), also described by Pallas . In 1832 Johannes Smuts described the species in the genus Bathyergus , but today it is again considered the only species in the genus Georychus .
No subspecies are currently distinguished within the species. On the basis of differences in molecular biological characteristics, however, it is discussed whether the populations in KwaZulu Natal and in the Western Cape represent separate species.
The scientific name of the genus, Georychus , means earth mover and is derived from the underground burrowing way of life. The species name capensis indicates the type locality on the Cape of Good Hope.
Hazard and protection
The Cape Blessmull is classified by the International Union for Conservation of Nature and Natural Resources (IUCN) as "Least Concern" (LC) and the stocks are assessed as stable. This is justified by the regular occurrence with stable populations; there are no known risks that could endanger the survival. In the region around Cape Town , the species occurs regionally with population densities of more than 30 individuals per square kilometer. In the montane habitats in KwaZulu-Natal and Mpumalanga, fragmented subpopulations have of course been identified; there may be other intermediate populations that have not yet been discovered.
The Cape Blessmull is partially classified as an agricultural and garden pest. The species occurs in several South African nature reserves and is therefore protected, for example it lives in the Western Cape Province in the West Coast National Park on Saldanha Bay and in KwaZulu Natal in the protected areas Kamiesberg and Mgeni Vlei .
supporting documents
- ↑ a b c d e f g h R.L. Honeycutt: "Cape Mole-Rat Georychus capensis " In: Don E. Wilson, TE Lacher, Jr., Russell A. Mittermeier (editor): Handbook of the Mammals of the World: Lagomorphs and Rodents 1. (HMW, Volume 6) , Lynx Edicions, Barcelona 2016; Pp. 367-368. ISBN 978-84-941892-3-4 .
- ↑ a b c d e f g h i j k l m n o p Nigel C. Bennett, Sarita Maree, Chris G. Faulkes: Georychus capensis. Mammalian Species 799, Aug. 9, 2006; Pp. 1-4 doi : 10.1644 / 799.1
- ↑ a b c Nigel C. Bennett: Genus Geomys - Cape Mole-Rat In: Jonathan Kingdon, David Happold, Michael Hoffmann, Thomas Butynski, Meredith Happold and Jan Kalina (eds.): Mammals of Africa Volume III. Rodents, Hares and Rabbits. Bloomsbury, London 2013, p. 662; ISBN 978-1-4081-2253-2 .
- ^ A b Colleen M. Ingram, Hynek Burda, Rodney L. Honeycutt: Molecular phylogenetics and taxonomy of the African mole-rats, genus Cryptomys and the new genus Coetomys Gray, 1864. Molecular Phylogenetics and Evolution 31 (3), 2004; Pp. 997-1014. doi : 10.1016 / j.ympev.2003.11.004
- ↑ a b c d e Nigel C. Bennett: Geomys capensis - Cape Mole-Rat (Blesmol) In: Jonathan Kingdon, David Happold, Michael Hoffmann, Thomas Butynski, Meredith Happold and Jan Kalina (eds.): Mammals of Africa Volume III . Rodents, Hares and Rabbits. Bloomsbury, London 2013, pp. 663-664; ISBN 978-1-4081-2253-2 .
- ↑ a b c d e Georychus capensis in the endangered Red List species the IUCN 2019 Posted by: S. Maree, J. Visser, NC Bennett, J. Jarvis, 2008. Accessed September 23 of 2019.
- ^ JH Visser, NC Bennett, B. Jansen van Vuurena: Distributional range, ecology, and mating system of the Cape mole-rat (Georychus capensis) family Bathyergidae. Canadian Journal of Zoology 95 (10), 2017: pp. 713-726. doi : 10.1139 / cjz-2017-0016 .
- ↑ Peter Simon Pallas : Novae species quadrupedum e glirium ordine, cum illustrationibus varies complurium ex hoc ordine animalium. W. Walther, Erlangen 1778; Pp. 172-174. ( Google Books )
- ^ Johann Karl Wilhelm Illiger : Prodromus systematis mammalium et avium additis terminis zoographicis utriusque classis, eorumque versione germanica. Berolini [Berlin]: sumptibus C. Salfeld, 1811; P. 81. ( digitized version )
- ↑ Georychus capensis . In: Don E. Wilson , DeeAnn M. Reeder (Eds.): Mammal Species of the World. A taxonomic and geographic Reference. 2 volumes. 3. Edition. Johns Hopkins University Press, Baltimore MD 2005, ISBN 0-8018-8221-4 .
literature
- Rodney L. Honeycutt: "Cape Mole-Rat Georychus capensis " In: Don E. Wilson, TE Lacher, Jr., Russell A. Mittermeier (editor): Handbook of the Mammals of the World: Lagomorphs and Rodents 1. (HMW, Volume 6), Lynx Edicions, Barcelona 2016; Pp. 367-368. ISBN 978-84-941892-3-4 .
- Nigel C. Bennett: Genus Geomys - Cape Mole-Rat and Geomys capensis - Cape Mole-Rat (Blesmol) In: Jonathan Kingdon, David Happold, Michael Hoffmann, Thomas Butynski, Meredith Happold and Jan Kalina (eds.): Mammals of Africa Volume III. Rodents, Hares and Rabbits. Bloomsbury, London 2013, pp. 662-664; ISBN 978-1-4081-2253-2 .
- Nigel C. Bennett, Sarita Maree, Chris G. Faulkes: Georychus capensis. Mammalian Species 799, Aug. 9, 2006; Pp. 1-4 doi : 10.1644 / 799.1
Web links
- Georychus capensis in the endangered Red List species the IUCN 2019 Posted by: S. Maree, J. Visser, NC Bennett, J. Jarvis, 2008. Accessed September 23 of 2019.