Great tenrek

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Great tenrek
Great tenrek (Tenrec ecaudatus)

Great tenrek ( Tenrec ecaudatus )

Systematics
without rank: Afroinsectiphilia
Order : Tenrecus (Afrosoricida)
Family : Tenreks (Tenrecidae)
Subfamily : Hedgehog treks (Tenrecinae)
Genre : Tenrec
Type : Great tenrek
Scientific name of the  genus
Tenrec
Lacépède , 1799
Scientific name of the  species
Tenrec ecaudatus
( Schreber , 1777)

The Great Tenrek ( Tenrec ecaudatus ), also Great Tanrek or simply Tenrek or Tanrek , is a species of mammal from the group of hedgehog tenreks , which belongs to the Tenrek family (Tenrecidae). He is the largest, most widespread and arguably best known representative of his family. Outwardly, it is characterized by a strong build and a large, wide head with a long muzzle. The fur is bristly, and there are spikes on the neck and head. The tail stub and long canine teeth are characteristic features. The animals' natural origin is Madagascar . There they occur in almost all habitats, they inhabit both the humid tropical rainforests in the eastern part and the deciduous dry forests of the western and the very dry thorn bush areas of the southwestern part of the island. They can adapt to landscapes changed by humans, so they also occur in urban areas. There are populations in Mauritius , Réunion , the Seychelles and the Comoros .

The way of life of the Great Tenrek is relatively well researched. He is nocturnal and ground dwelling. As a shelter, he uses tunnels he dug himself and which are equipped with a nest of plants. There he also spends the dry and nutrient-poor southern winter in a state of rigidity ( torpor ) that can last for several months. The general rhythm of life is accompanied by strongly fluctuating body temperatures, which depend on the outside temperature and the activity. The animals are solitary and only come together during the breeding season. A litter consists of an average of 15 young, a maximum of 32 have been observed so far, which is the highest number among mammals. The young animals have a striped fur, which also has significantly more spines. On the rear part, the spines are transformed into a stridulation organ with which they can produce rattling sounds. The rearing of the young takes about two months. The diet of the great tenrec is mainly based on invertebrates such as insects and worms , and it also consumes small vertebrates and plant material such as fruits.

The Great Tenrek was mentioned in Europe as early as the middle of the 18th century, its first scientific description as a species dates back to 1777. Although the genus was named Tenrec about two decades later, the Great Tenrek was in the course of the 19th century known under the younger name Centetes . The name that is valid today did not establish itself until the middle of the 20th century. The population of the Great Tenrec is considered to be safe, but locally there may be declines due to intensive hunting.

features

Habitus

The great tenrek is the largest representative of the tenreks. Adults have a head-to-trunk length of 26.5 to 39 cm and a 1.0 to 1.5 cm long tail. The body weight varies from 600 to 2400 g depending on the season, animals in captivity can weigh up to 3000 g. Males are usually slightly heavier than females. The body is very muscular. There is no real spiky dress on the back, just a bristly fur made of 27 to 60 mm long hair, which is interspersed with shorter, 8 to 15 mm long spines. On the neck and on the head, the spines, which can be short and thick (10 to 15 mm) or long and slender (18 to 24 mm), are more dense. The thorn density usually decreases with the age of the animals. Long, black hairs protrude from the fur as tactile organs. The color of the fur on the back varies depending on the geographical region and ranges from reddish to yellowish to agouti brown. Females are usually a little darker in color than males. The underside is sparsely hairy and cream-colored. The head is light brownish and relatively large, it takes up almost a third of the total length of an animal. The great tenrek is also very broad. There is a clear sexual dimorphism , since the eyes of males are significantly further apart. The broad face of the males is caused by the powerful masseter muscle . In addition, the muzzle is elongated and equipped with distinctive vibrissae . The front legs are longer than the rear legs, the hands and feet each have five rays and short, strong claws. The females have 12 to 14 pairs of teats .

Young animals differ significantly from adult individuals. Up to a body length of 16 cm they have a dark brown back color, which is interrupted by five longitudinal stripes of whitish spines. On the center line there is a stridulation organ similar to that found in the striped duck. It extends over a length of 40 mm and a width of 2 mm and consists of 30 to 80 spines. These are in three to five rows and have a cream-colored tint. Here they are embedded in special subcutaneous muscles and can rub against each other by tensing the muscles, producing sounds. In the transition to the adult animal, the stripe pattern and the stridulation organ are lost and are replaced by simpler hair and bristles.

Skull and dentition features

Skull of the Great Tenrec

The skull is elongated and cylindrical with an extended rostrum . The brain skull, on the other hand, has a short, narrow and angled structure, and here there are also strong bones in the sagittal and lambda regions. The ratio of anterior to posterior skull section is 0.64: ​​0.36. The interocular region is relatively narrow and elongated. The zygomatic arch is not closed, a typical characteristic of all tenreks. The dentition consists of 38 teeth with the following dental formula : . In the upper row of teeth there are short diastemas on both sides of the canine and behind the first premolar , in the lower row there is no gap in front of the canine. The upper two first cutting teeth are similar in their size, the third one is only in the primary dentition present, significantly smaller than the front and in the duration of teeth no longer present. In the lower jaw, all the incisors are rather small, only the middle one is slightly higher. The invicisives are characterized by additional small cusps on the tooth crowns. These are missing in the canine, which therefore looks like a real canine ( canin-shaped ). In addition, it is extremely large in both the upper and lower dentition, it can be up to 15 mm long in males. In the intermaxillary bone, invaginations are formed that accommodate the lower canine when the dentition closes. The anterior two premolars are conical in shape, the last one clearly resembles the molars . The molars are characterized by a zalambdodont chewing surface pattern consisting of three main cusps (para-, proto- and metaconus; based on the maxillary molars) in a triangular arrangement.

Skeletal features

Skeleton of the Great Tenrec

The spine is made up of 7 cervical, 17 to 19 thoracic, 4 to 7 lumbar, 2 to 3 sacrum and 8 to 10 caudal vertebrae. The largely generalized, ground-dwelling way of life of the Great Tenrek can also be seen in the skeleton structure. The shoulder blade has a short and high shape and thus differs from the long, narrow burrowing tenreks. The upper arm bone of the Great Tenrek is significantly longer than the spoke compared to other Tenreks . He has a massive, large rolling mound, which speaks for powerful longitudinal movements of the front leg. On the other hand, the small rolling mound is rather smaller, as the point of attachment of the subscapularis muscle , this indicates that the arm is less able to rotate. The deltopectoral ridge on the humeral shaft also shows little development. The lower joint end ( elbow joint ) is comparatively wide. Since part of the forearm muscles originate here, a certain ability to scratch and dig can be inferred. This is also supported by the relatively long upper articular process ( olecranon ) of the ulna , which makes up about 23% of the length of the total bone. The joint end at the lower end of the shaft for articulation by hand is rather wide and flat. There are no adhesions on the carpal bones , as has been demonstrated in some burrowing species. They also have a rather long shape, while the phalanges appear short. The prepollex , a finger-like extension on the large polygon to the inside of the thumb, is very long. The claws, in turn, appear very long and flat, they are not as strongly curved as in tree-climbing tenreks. At the rear of the foot, the slightly arched ankles indicate greater restrictions in freedom of movement, and the strong neck of the ankle bone speaks for terrestrial locomotion. In contrast, the rounded head of the talus indicates a certain ability to climb.

distribution and habitat

Distribution of the Great Tenrec

The great tenrek is endemic to all of Madagascar . It occurs in almost all forest landscapes on the island, from the humid tropical rainforests in the east to the deciduous dry forests of the west to the very dry thorn bush areas of the southwest. In the forests of western Madagascar, the species could be detected in almost all investigated places (35 of 37 locations). In addition, it can also be found on plantations, on farmland, in secondary open forest landscapes and in urban areas. The animals prefer habitats with water nearby and dense ground cover that serves as cover. The altitude distribution ranges from sea level to around 2050 m. The species is also common on the Comoros , where its origin is considered unclear. It was introduced as a food resource in the Mascarene Islands ( Mauritius and Réunion ), as well as in the Seychelles , where it has been recorded since around 1880. The animals are still hunted on the first two groups of islands, but not on the latter. There the population density in beneficial habitats can be up to 15 individuals per hectare .

Way of life

Territorial behavior

Large tenrek with raised bristles

The way of life of the great tenreks is relatively well researched, it was studied in free range animals in Madagascar and the Seychelles. They are mainly nocturnal with a bimodal distribution : the first phase of activity takes place in the early evening between 7:30 and 9:00 p.m. with a peak at 8:00 p.m. The second runs from 12:30 a.m. to 5:00 a.m. with the main activity from 1:00 a.m. to 2:00 a.m. Viewed over the year, the animals also have cyclical activity. In the southern winter (May to October), when food resources decline, they decay into a torpor that can sometimes last for up to six months. The Great Tenrek is floor-dwelling and moves forward in the cloister . He is also good at swimming and crosses rice fields. He has also been observed climbing rocks, but you almost never see him on trees. The Great Tenrek moves slowly forward in unknown terrain, pauses frequently and sniffs constantly in the air, sometimes he lifts a foreleg, but otherwise remains motionless. Sometimes it also emits whistle-like sounds, which are probably used for communication with other species. By clicking their tongues, the animals can generate high-frequency sounds in the range from 10 to 16  kHz and with a duration of 0.1 to 3.6 ms. They are probably part of a simple echolocation that the animals also use to orient themselves. In contrast to other tenreks, the great tenrek's sense of sight is better developed and is also actively used.

The Big Tenrek uses individual activity areas of 1 to 3 hectares in size, the dimensions depend on the food supply. They overlap with those of other individuals in the border area. The animals spend their resting time in natural or self-dug underground burrows. The burrows vary depending on the season, age and gender. One of two investigated structures near Ivohibe in southeastern Madagascar, which were in use during the southern winter, had a length of around 2 m, with the first one and a half meters running flat below the ground and the tunnel then bending downwards and 30 cm below the ground ended. The entrance was covered with leaves. Females with offspring create more complicated and deeper tunnels that have two entrances so that the burrow is Y-shaped. Males, on the other hand, probably use flatter burrows. The tunnels are often located on river slopes under tree roots or fallen trees. They end up blind in a nest chamber made of plant material. Some of the measured nest chambers were 8 to 13 cm long, 13 to 18 cm wide and 7 to 11.5 cm high. The plant parts are transported by the animals in the mouth. There is a largely balanced climate in the tunnels. The inside temperatures at depths of 6 to 8 cm are 19.7 to 25.5 ° C with outside temperatures of 18 to 29 ° C. To sleep, the animals curl up on their hind legs or, less often, lie to the side, and at high temperatures they take a stretched position. The comfort behavior consists of scratching with the hind foot and licking. The "face washing" with both front legs, which is sometimes typical for other hedgehog tenreks and also the small tenreks ( microgale ), does not occur in the large tenrek.

Preparation of a great tenrec in defensive stance

In general, the great tenrek lives solitary, with the exception of groups of mother and young animals, while males and females sometimes stay together for up to three days during mating. Same-sex conspecifics avoid encounters with one another. If this does happen, the animals inspect each other for a short time, sometimes accompanied by puffing sounds, and then separate again. With aggressive behavior, the spines are set up on the neck and bite attacks occur. A torn open mouth, the span of which can be up to 13 cm, and a foot stomp serve as a threatening gesture. The other phonetic communication includes grunts and sibilants, which are often uttered in distress. In addition, communication takes place via chemical stimuli. The great tenrek often defecates next to the entrances to his burrows . Sometimes he digs small holes with his front legs and buries his excrement in them with kicking movements of the back legs. Mothers mark their burrows when they leave, sometimes with the participation of their offspring. When encountering conspecifics or in unfamiliar terrain, the animals rub their rear or sides against objects.

Diet and energy balance

The great tenrek is an omnivore that primarily eats invertebrates such as insects and worms . Investigations of 22 stomach contents from the forest area of ​​Kirindy in western Madagascar revealed a large proportion of ants , including the genera Pachycondyla , Camponotus , Monomorium and Pheidole , and termites , such as Coarctotermes . Also common were centipedes and various developmental stages of beetles , dominated here scarab beetles and plant bugs . Another five stomach contents, which had already been analyzed in the 1930s, mainly contained caterpillars and beetles. In addition, the food spectrum also includes earthworms and grasshoppers . The Great Tenrek also consumed smaller vertebrates , for example frogs , lizards or mice , and sometimes also bird eggs, and animals in captivity also ate raw meat. Plants also play a certain role; they are mainly consumed in the form of fruits towards the end of southern summer, when the animals are getting fat.

Overall, the main diet consists of small prey animals with a specialization in arthropods . Larger prey such as vertebrates are more likely to be hunted down by chance on occasion. When foraging for food, the great tenrek strides slowly forward, searching under the fallen leaves and dead trees on the ground. It often digs small holes 5 cm deep, its most important prey animals live up to a maximum of 10 cm below the surface of the earth. The snout plays an important role in tracking down the prey. It is covered with whiskers and warty humps that have a tactile function. The good sense of smell is also used, since the nose is only a few millimeters above the ground when searching, but the sense of sight is also better developed than with most other tenreks. Smaller prey such as ants and termites are picked up with the long and flexible tongue and immediately chewed. The pointed cusps of the molars are specially adapted for insect food, but they are also able to break up smaller vertebrates. Vegetable material can only be cut up with the teeth, but not ground. Therefore, the primary digestion and dissolution of the plant cells is more likely to take place in the gastrointestinal tract. In general, the main manipulation of food takes place with the mouth, the front paws hardly play a role.

Comparable to other representatives of the tenreks, the great tenrek also has a varying body temperature that changes cyclically over the day and year. Laboratory tests from the 1950s showed a range between 24.1 and 34.8 ° C with an average of 28.4 ° C. The ambient temperatures ranged from 12 to 24.4 ° C. At that time, however, observations on an adult animal hardly revealed any relationship between the environment and the activity; only one young animal became lethargic at body temperatures below 25 ° C. However, other studies showed clear links between outside and body temperature. For example, the body temperature within a day was 15.2 and 28.1 ° C, only a few degrees above the outside temperature of 12 to 27 ° C. Studies under almost natural conditions at Perinet in central-eastern Madagascar yielded similar results. In animals in the Seychelles, the body temperature in active animals fluctuates from 23 to 35.5 ° C, the highest values ​​occur in individuals during nocturnal feeding. As a result, the various studies indicated that the body temperature of the great tenrek depends on the ambient temperature and the activity of an animal. Deviating from this, a study from 2019 found strongly variable body temperatures in the Great Tenrek during the day with maximum values ​​between 12 and 34 ° C. Accordingly, the body temperature approaches the outside temperature down to a minimum of 12 ° C, even in physically active animals. The lower the ambient temperature, the more violent the fluctuations. The body temperature stabilizes over certain short periods of the day, regardless of this, pregnant females show a less strongly varying body temperature, especially shortly before and during the birth phase. On the other hand, individual individuals experience lethargic moments during their period of activity at body temperatures of around 28 ° C, which can last for several hours to days. In the case of external disturbances, however, a waking state occurs relatively quickly again, which in turn is often associated with a slight increase in body temperature. In general, the great tenrek proves to be intolerant of outside temperatures of below 8 or above 34 ° C and then develops symptoms of stress . In conclusion, it can be said that although body temperature contributes to the animals' activity cycle, it does not fully control it.

The animals spend the southern winter or the dry season in Madagascar in a torpor . The period extends roughly from May to October and is characterized by a sharp decline in the food supply. In the Ankarafantsika National Park, animals were observed that spent a total of eight to nine months in a state of rigidity (from February / March to November). It is noteworthy that the interruption of the torpor, which usually occurs every 12 to 24 hours and protects the animals from long-term damage such as circulatory or metabolic disorders , does not occur in the Great Tenrek as long as the body temperature is above 22 ° C. In the Seychelles, the Great Tenrek also shows a phase of rigidity. It takes place largely from January / February to July / August and lasts at least six months. Here, too, the phase is associated with a strong dwindling of food resources, which is associated with the change of the monsoons from northwest to southeast. Male animals start their torpor on average one month earlier than females. The slight time shift also shows that the Great Tenrek can adapt to different local conditions. A cyclical course of the body temperature is also noticeable during the rigid period, as a rule it is only a few degrees above the outside temperature. Occasional sharp increases in body temperature up to a maximum of 32 ° C at night can be associated with occasional activities of the animals. Sometimes the animals dig a new chamber, which can be up to 1 m away from the old one. As a rule, however, the animals remain in the same shelter for the entire duration of the torpor; a possible change of location only occurs in the event of heavy rainfall or other external influences. At the end of the torpor phase there is a gradual rise in body temperature that lasts for several weeks. The waking up phase depends on the external conditions and can be completed within a few seconds at higher ambient temperatures, but correspondingly longer at lower outside temperatures. In addition to the body temperature, the breathing rate also drops to up to 30 breaths per minute during the state of rigidity, and the heart rate can also decrease by 34%. The seasonal activity and inactivity of the Great Tenrec is accompanied by a cyclical change in body weight. The weight of the animals increases drastically before the start of the rigid period, some individuals then have a fat percentage of up to 50% of their body weight. This is achieved in part with increased intake of fruit. The body weight then falls again during the torpor phase by 1.1 to 1.4 g per day.

Reproduction

Photo of a group of tenreks in the undergrowth
A family of the great tenreks

The reproductive phase begins immediately after the end of the drought in spring (September to October); depending on the geographical location, it can shift by about a month. It starts a month earlier in the more tropical Seychelles. There are pronounced rival fights between the males for the privilege of mating. The fights are ritualized with the long canine teeth, which can also lead to injuries. The neck bite observed in other tenre cards is modified in the great tenrek and the animals throw their heads to the side during the fights. The winner woos the female by following her and sniffing her at various points, starting at the nose over the sides. This is accompanied by grunts. The sexual act begins with the rise of the male on the female . It lasts about 4½ to 12 minutes, but can also last 25 minutes and is interrupted several times.

The gestation period is 58 to 64 days, the duration is probably influenced by the torpor of the mother animal, which is also proven by the Erdtenrek ( Geogale ). Around 25% of all pregnant females show polyovulation , in which up to 5 egg cells are stored in the follicle . Another special feature is that the follicles do not fill with fluid to form a Graafian follicle. Rather, the solid follicle slowly tears open and the egg cell migrates to the surface for fertilization. Shortly before birth, the female increases her nest-building activities and constructs a spherical plant nest in the rearmost part of the burrow. On average, 15 young animals are born, but the litter size can be up to 32, the record among mammals. Generally, tenreks from the dry south and southwest of Madagascar have larger litters than those from the wetter east. Studies from the Seychelles also showed smaller litter sizes with a maximum of 18 to 20 cubs. In addition, the litter size decreases with increasing age of the animals; females in the third reproductive period give birth to fewer young on average than those in the first due to intrauterine mortality or resorption of individual fetuses .

Pups come as Nesthocker blind and deaf to the world, but they are more developed than in most other tenrecs. They are covered with a characteristic, light-dark striped fur made of 5 mm long hair and have well-developed claws. The birth size is 84 to 92 mm, the weight is 22.8 to 27.4 g. They can also make hissing and squeaking sounds and crawl around on all fours. The mother animal is particularly vigilant at first and defends the nest with an erect ruff, bites and foot stomps. She often licks her offspring and stands protectively over the boy to suckle. On the seventh day, clear spines can be seen in the light stripes of fur; they are particularly prominent on the stridulation organ in the middle of the back. From the ninth day the eyes begin to open, but the process continues until the 14th day. A scratch reflex is developed after 11 days, and a young animal can already coordinate its front and rear legs better at this point. At the age of three weeks, the cubs take their first forays to look for food with their mother. The stripes on the cubs have a camouflaging character. They run in a row behind the mother and clench around her when she eats or stops, such as when there is a possible danger. In the latter, the young then stridulate, which is connected with the erection of the spines and flight. The function of stridulation in young animals is not fully understood; they may also use it to transmit information about their location or warn other nest members. The frequencies generated by the rattling noises of the spines are in the range of 12 to 15 kHz. The weaning period also begins in this period, when the young animals have reached up to 40 times their birth weight. At around 35 days, the mother's attention decreases and the young are more likely to go foraging alone. From then until the 60th day, the fur changes and the young get the coat of the old animals. They are then on average 16 cm long at the beginning of this process. Then the cohesion of the family group dissolves. The maximum life expectancy of animals in human captivity has so far been almost nine years; hardly any data is available for animals in the wild. Only a few females reached the age of four in the Seychelles.

Predators and parasites

The fossa is one of the most important predators , but according to analyzes of 114 faecal samples from the predator from the Kirindy forest, the great tenrek only achieves a small proportion of individuals and biomass in the entire prey spectrum (around 2.5% each). The species was also rarely captured by the fossa in the Ankarafantsika National Park, and most of the animals were also killed in the southern summer. The Madagascar buzzard and the northern Madagascar boa are also important . In contrast to the large or small hedgehog tenrek, the large tenrek can not curl up into a ball. In the event of an attack or contact, he straightens the hair on the back of his neck, makes hissing or squeaking noises and stamps his feet. He also shows an open mouth or bites. As a rule, however, an animal flees and can reach speeds of 3.6 to 4.7 km / h. As external parasites fleas of the genus are Paractenopsyllus and mites of the genus Andrea Carus identified internal parasites include, besides nematodes including the protozoa Eimeria a. In addition, the great tenrek occurs as a host of Leptospira bacteria.

Systematics

Internal systematics of the Tenreks according to Everson et al. 2016
 Tenrecidae  
  Tenrecinae  


 Echinops


   

 Setifer



   

 Hemicentetes 


   

 Tenrec ecaudatus




   
  Geogalinae  

 Geogals


  Oryzorictinae  

 Oryzorictes 


   

 Nesogale


   

 Microgale






Template: Klade / Maintenance / Style

The Great Tenrek is a kind from the genus Tenrec , in turn, to the family of tenrecs belongs (Tenrecidae). Within this it forms together with the large hedgehog trek ( Setifer setosus ), the small hedgehog trek ( Ehinops telfairi ) and the striped duck trek ( Hemicentetes ) the subfamily of the hedgehog trek (Tenrecinae). The hedgehog tenreks represent one of the three main lines of the tenreks. Their spiky coat sets them apart from the other soft-haired tenreks such as the very diverse rice burrowers (Oryzorictinae) and the monotypical Erdtenreks (Geogalinae). According to molecular genetic studies, the great tenrec is more closely related to the striped tenrek. In addition to the less spiky coat in comparison to the hedgehog tenreks, both genera combine the stripe pattern and the ability to stridulate, both of which are only developed in the large tenreks, however. Opposite them, in turn, is a clade made up of the large and the small Igeltenrek. A closer relationship between the Great Tenrek and the Striped Tenreks was also considered for morphological reasons. The lines of the Great Tenrec and the Striped Tenrec separated as early as the end of the Lower Miocene about 16.1 million years ago.

The genus Tenrec contains only one species, and no subspecies of the Great Tenrec are known. Both genus and species are therefore to be regarded as monotypical .

Tenrec and Centetes - On the research history of the genus

Johann Christian von Schreber
Schreber's portrayal of the Great Tenrec

For the first time in Europe, Etienne de Flacourt , the former governor of Madagascar, reported on Tenreks. In his travelogue published in 1658 and reprinted several times, he mentioned a hedgehog-like animal and referred to it as "Tendrac". Today the "Tendrac" is generally associated with the Great Igeltenrek . A good hundred years later, Georges-Louis Leclerc de Buffon described the "Tendrac" more precisely in the twelfth volume of his work Histoire naturelle, générale et particulière in 1764 and put the "Tanrec" at his side. The work also contained illustrations of the two forms. According to Buffon, the "Tanrec" was significantly larger than the "Tendrac", it also had a longer snout and only had spikes in the neck, while the rest of the body was covered by bristles. Buffon's remarks on "Tendrac" and "Tanrec" were based on two animals that were at the time in the Cabinet du roi , the predecessor of the Muséum national d'histoire naturelle in Paris, and came from a gift from a merchant in Lyon. According to later information, the "Tanrec" had a length of 21 cm. In 1777, Johann Christian von Schreber then presented a German-language description of the "Tanrec" in his comprehensive work Die Säugthiere in images based on nature with descriptions . He relied on Buffon and also provided his descriptions with an illustration that was based on those from the Histoire naturelle . The illustration also contained the scientific name Erinaceus ecaudatus , which is why Schreber is considered the first to describe the Great Tenrec. The species name ecaudatus is of Latin origin and refers to the barely visible tail (from ecaudis for "tailless", derived from cauda for "tail").

Bernard Germain Étienne Médard de La Ville-sur-Illon, comte de La Cépède

With the species name Erinaceus ecaudatus, Schreber put the "Tanrec" to today's small ear hedgehogs . The assignment of the then known forms of tenreks to the hedgehogs was quite common in the late 18th century. A good two decades after Schreber's publication in 1798, Georges Cuvier formally separated the Tenreks ( Tenrecs ) from the hedgehogs ( Hérissons ) for the first time , but did not name a new genus. This was then reserved for Bernard Germain Lacépède the following year, who coined the generic name Tenrec for the Great Tenrek. He characterized the genus over three incisors of the same size, a canine tooth three times as long and over the spiked body. Johann Karl Wilhelm Illiger established the genus Centetes in 1811 and, like Lacépède with Tenrec before, put it in direct relation to Erinaceus ecaudatus . His description of features was similar to that of Lacépède, with Illiger also highlighting the long muzzle and the five-pointed hands and feet. The name Centetes is taken from the Greek language ( κεντητήϛ kentetes ) and is derived from κεντητος ( kentetos ) for “embroidered” or κεντεω ( kenteo ) for “sting”. On Illigers Centetes the name also created by Georges Cuvier based Centenes who was occasionally in use, but is regarded as a misspelling. By Anselme Gaëtan Desmarest again the name comes Tenrecus which he introduced in 1820 and attributed Lacépède.

The generic name Tenrec was largely ignored by most authors after its introduction by Lacépède. Rather, Centetes found widespread use in the 19th century and was a valid generic name until the middle of the 20th century. The family name Centetidae, which Andrew Murray created in 1866, is based on Centetes . Murray set the tenreks away from the hedgehogs, he included all tenrek genera known at the time in the Centetidae ( Centetes , Ericulus and Echinogale ; today under Tenrec , Setifer and Echinops ). Before that, Charles Lucien Jules Laurent Bonaparte had already incorporated the Centetina as a subgroup of the hedgehogs in 1838 . In 1945, George Gaylord Simpson pointed out in his Taxonomy of Mammals that Centetes is not valid as a generic name, as Tenrec was already named before.

The independence of the Great Tenrec has never been the subject of scientific dispute and is generally recognized. Only George Shaw saw the shape as a variety of the striped duck in 1800, but this was hardly recognized. In 1837, Saint Hilaire introduced Centetes armatus in a few words . Only two years later he described the shape more precisely, it was based on an individual that had been given to the Muséum national d'histoire naturelle by a French naval captain. However, hardly any differences to the Great Tenrek could be made out, so that Centetes armatus was already synonymous with Tenrec ecaudatus in the 19th century . Another, rarely used synonym is Erinaceus tanrec, used by Pieter Boddaert as early as 1785 .

Tribal history

As a rule, the tenreks are rarely detectable in fossil form. This also applies to the Great Tenrek. A single lower jaw of a non-adult animal was discovered in the Ankilitelo Cave . The cave is located on the southern edge of the Mikoboka Plateau north of Toliara in southwestern Madagascar. It has been scientifically investigated since 1994. Its very rich fauna is made up of bones and teeth from various primates , bats and rodents , and around half a dozen species of tenreks have been passed down. The large tenrek is a rather rare element of fauna compared to the large and small hedgehog tenrek, the earth tenrek ( geogale ) or the various representatives of the small tenreks ( microgale ). The age of the finds is around 510 to 630 years. Another point of discovery is the Andrahomana Cave in the extreme southeast of Madagascar. This is embedded in the Eolianite outcrops of the cliffs and has been explored since the end of the 19th century. Its fossil material, which is also extremely rich and covers the past 8,700 years, includes reptiles , birds and mammals , including several tenrek species such as the great tenrek. Mainly dry climates prevail in both find regions, but in the area of ​​the Andrahomana Cave the humid conditions of eastern Madagascar still have an effect.

threat

ready-to-use large tenrek

The Great Tenrek is a cultural follower to a certain extent and occurs on agricultural and farmland as well as in human settlements. The clearing of forests does not have a major impact on the population of the species, but forest fires can be a local threat in the dry forests of the southwest. In large areas of Madagascar, the great tenrek is hunted for its meat. In some areas, mainly around larger cities, it may therefore have disappeared due to being overhunted. Regionally there are individual taboos with regard to the hunt for the Great Tenrek , for example in central-eastern Madagascar, where the animals can only be hunted at the end of the southern summer in April / May. The animals on the Mascarene Islands are also considered a food resource, while on the traditionally Islamic Comoros they were subject to a taboo for a long time, but this seems to have been relaxed recently. The IUCN classifies the Great Tenrek as “not endangered” ( least concern ) due to its wide distribution and its adaptability . It occurs in almost all protected areas of Madagascar, among the most important about the Amber Mountain National Park , the National Park Marojejy , the Masoala National Park , the National Park Ankarafantsika , the Isalo National Park , the National Park Zombitse , the Ranomafana National Park , the National Park Andringitra and the Andohahela National Park .

The species has not been kept in Germany since it was stopped in Stuttgart in 2015. In Europe you can see them in France, Great Britain, Poland and the Czech Republic.

literature

  • JF Eisenberg and Edwin Gould: The Tenrecs: A Study in Mammalian Behavior and Evolution. Smithsonian Institution Press, 1970, pp. 1-138
  • Kathryn M. Everson, Voahangy Soarimalala, Steven M. Goodman and Link E. Olson: Multiple loci and complete taxonomic sampling resolve the phylogeny and biogeographic history of tenrecs (Mammalia: Tenrecidae) and reveal higher speciation rates in Madagascar's humid forests. Systematic Biology 65 (5), 2016, pp. 890-909 doi: 10.1093 / sysbio / syw034
  • Nick Garbutt: Mammals of Madagascar. A complete guide. Yale University Press, 2007, pp. 1–304 (pp. 32–56)
  • Paulina D. Jenkins: Tenrecidae (Tenrecs and Shrew tenrecs). 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. 134–172 (p. 164) ISBN 978-84-16728-08-4
  • Martin Nicoll: The common tenrec, Tenrec ecaudatus. Afrotherian Conservation 7, 2009, pp. 2-3
  • Ronald M. Nowak: Walker's Mammals of the World . The Johns Hopkins University Press, Baltimore 1999, ISBN 0-8018-5789-9

Individual evidence

  1. ↑ a b c d e f g h i j k l m Martin Nicoll: The common tenrec, Tenrec ecaudatus. Afrotherian Conservation 7, 2009, pp. 2-3
  2. ↑ a b c d e f g h i j Nick Garbutt: Mammals of Madagascar. A complete guide. Yale University Press, 2007, pp. 1–304 (pp. 32–56)
  3. ↑ a b c d e f g h i j k l m n J. F. Eisenberg and Edwin Gould: The Tenrecs: A Study in Mammalian Behavior and Evolution. Smithsonian Institution Press, 1970, pp. 1-138
  4. ↑ a b Olga V. Zherebtsova: Morphofunctional interpretation of the quills stridulating in tenrecs (Lipotyphla, Tenrecidae). Russian Journal of Theriology 5 (1), 2006, pp. 1-11
  5. ^ A b c George Edward Dobson: A Monograph of the Insectivora, systematic and anatomical. Part I. London, 1883, pp. 68-69 ( [1] )
  6. ↑ a b c d e Konrad Herter: About the hedgehogs of Madagascar (Tenrecinae). Meeting reports of the Society of Friends of Natural Sciences in Berlin NF 2, 1962, pp. 5-37
  7. ^ A b Walter Poduschka: Hyperthelia, litter size and gestation duration in the subfamily Tenrecinae Cabrera, 1925 (Mammalia: Insectivora: Tenrecidae), together with remarks on the longitudinal striations of the genus Hemicentetes. Contributions to Zoology 66 (2), 1996, pp. 119-128
  8. ↑ a b c d e f g h i j k l m Paulina D. Jenkins: Tenrecidae (Tenrecs and Shrew tenrecs). 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. 134–172 (p. 164) ISBN 978-84-16728-08-4
  9. ^ A b c Edwin Gould: Evidence for echolocation in the Tenrecidae of Madagascar. Proceedings of the American Philosophical Society 109 (6), 1965, pp. 352-360
  10. ↑ a b c Wilhelm Leche: On the history of the development of the mammalian tooth system, at the same time a contribution to the tribal history of this group of animals. Part two: phylogeny. Second booklet: Families of the Centetidae, Solenodontidae and Chrysochloridae. Zoologica 20, 1906/1908, pp. 1–157 ( [2] )
  11. ↑ Steven M. Goodman and Paulina D. Jenkins: Tenrecs (Lipotyphla; Tenrecidae) of the Parc National de Marojejy, Madagascar. Fieldiana Zoology 97, 2000, pp. 201-229
  12. ^ Justine A. Salton and Eric J. Sargis: Evolutionary morphology of the Tenrecoidea (Mammalia) carpal complex. Biological Journal of the Linnean Society, 93, 2008, pp. 267-288
  13. ^ Justine A. Salton and Eric J. Sargis: Evolutionary Morphology of the Tenrecoidea (Mammalia) Forelimb Skeleton. In: EJ Sargis and M. Dagosto (Eds.): Mammalian Evolutionary Morphology: A Tribute to Frederick S. Szalay, Springer Science, 2008, pp. 51-71
  14. ^ Justine A. Salton and Frederick S. Szalay: The Tarsal Complex of Afro-Malagasy Tenrecoidea: A Search for Phylogenetically Meaningful Characters. Journal of Mammalian Evolution 11 (2), 2004, pp. 73-104
  15. ↑ Voahangy Soarimalala: Les Afrosoricides de la forêt sèche malgache. Afrotherian Conservation 8, 2011, pp. 4-9
  16. ^ David Ross Stoddart : Biogeography and ecology of the Seychelles Islands. Springer, 1984. ISBN 906193107X , p. 616
  17. ^ A b P. J. Stephenson, Voahangy Soarimalala and Steven M. Goodman: Tenrec ecaudatus. The IUCN Red List of Threatened Species 2016. e.T40595A97204107 ( [3] ); last accessed on April 18, 2017
  18. ↑ a b A. L. Rand: On the Habits of Some Madagascar Mammals. Journal of Mammalogy 16 (2), 1935, pp. 89-104
  19. ^ JJ Petter and A. Petter-Rousseaux: Notes biologiques sur les Centetinae. La Terre et la Vie 17 (1), 1963, pp. 66-80
  20. ^ A b Edwin Gould and John F. Eisenberg: Notes on the biology of the Tenrecidae. Journal of Mammalogy 47 (4), 1966, pp. 660-686
  21. ↑ a b M. Ade: Examination of the digestive tract contents of Tenrec ecaudatus Schreber 1777 (Tenrecidae, Insectivora) from Western Madagascar. Primate Report 46-1, 1996, pp. 233-249
  22. ^ M. Eisentraut: Temperature fluctuations in lower mammals. Zeitschrift für Mammalkunde 21, 1956, pp. 49-52
  23. ↑ C. Kayser: Consommation d'oxygène et temperature central au cours de l'hiver austral de deux insectivores de Madagascar, Centetes ecaudatus et Setifer setosus. Comptes rendus des séances de la Société de Biologie 154, 1960, pp. 1873–1876 ( [4] )
  24. ↑ a b c Martin Nicoll: Responses to Seychelles tropical forest seasons by a litter-foraging mammalian insectivore, Tenrec ecaudatus, native to Madagascar. Journal of Animal Ecology 54, 1985, pp. 71-88
  25. ^ A b c Martin Nicoll: Diel variation in body temperature in Tenrec ecaudatus during seasonal hypothermia. Journal of Mammalogy 67, 1986, pp. 759-762
  26. ↑ a b c d Michael D. Treat, Lori Scholer, Brandon Barrett, Artur Khachatryan, Austin J. McKenna, Tabitha Reyes, Alhan Rezazadeh, Charles F. Ronkon, Dan Samora, Jeremy F. Santamaria, Claudia Silva Rubio, Evan Sutherland, Jeffrey Richardson, John RB Lighton and Frank van Breukelen: Extreme physiological plasticity in a hibernating basoendothermic mammal, Tenrec ecaudatus. Journal of Experimental Biology 221, 2018, S. jeb185900 doi: 10.1242 / jeb.185900
  27. ↑ a b Barry G. Lovegrove, Kerileigh D. Lobban and Danielle L. Levesque: Mammal survival at the Cretaceous-Palaeogene boundary: metabolic homeostasis in prolonged tropical hibernation in tenrecs. Proceedings of the Royal Society B 281, 2014, S. 20141304 doi: 10.1098 / rspb.2014.1304
  28. ^ A b John F. Eisenberg: Tenrecs and solenodons in captivity. International Zoo Yearbook 15, 1975, pp. 6-12
  29. ^ Martin Nicoll and PA Racey: Follicular development, ovulation, fertilization and fetal development in tenrecs (Tenrec ecaudatus). Journal of Reproduction and Fertility 74 (1), 1985, pp. 47-55
  30. ↑ Richard Weigl: Longevity of mammals in captivity; from the Living Collections of the world A list of mammalian longevity in captivity. Kleine Senckenberg series, Volume 48, 2005, pp. 1–214 (p. 35)
  31. ↑ Rodin M. Rasoloarison, Bernardin PN Rasolonandrasana, Jörg U. Ganzhorn and Steven M. Goodman: Predation on vertebrates in the Kirindy forest, Western Madagascar. Ecotropica 1, 1995, pp. 59-65
  32. ^ Luke Dollar, Jörg U. Ganzhorn and Steven M. Goodman: Primates and other prey in the seasonally variable diet of Cryptoprocta ferox in the deciduous forest of Western Madagascar. In: S. Gursky and KA Nekaris (eds.): Predation on primates. New York, 2007, pp. 63-76
  33. ↑ Clare E. Hawkins and Paul A. Racey: Food habits of an endangered carnivore, Cryptoprocta ferox in the dry deciduous forests of Western Madagascar. Journal of Mammalogy 89 (1), 2008, pp. 64-74
  34. ↑ Jean-Claude Beaucournu, H. Rico Randrenjarison Andriniaina and Steven M. Goodman: Puces (Insecta: Siphonaptera) d'Ambohitantely, Madagascar: Spécificité et phenologie. Malagasy Nature 9, 2015, pp. 39-48
  35. ↑ Michael W. Hastriter and Carl W. Dick: A description of Paractenopsyllus madagascarensis sp. n. and the female of Paractenopsyllus raxworthyi Duchemin & Ratovonjato, 2004 (Siphonaptera, Leptopsyllidae) from Madagascar with a key to the species of Paractenopsyllus. ZooKeys 13, 2009, pp. 43-55
  36. ↑ Ashley PG Dowling, Andre V. Bochkov and Barry M. Oconnor: Revision of the genus Andreacarus (Acari: Laelapidae) with description of seven new species and a new genus for Australian species formerly placed in Andrreacarus. Journal of Medical Entomology 44 (3), 2007, pp. 405-421
  37. ↑ Lee Couch, Juha Laakkonen, Steven Goodman, and Donald W. Duszynski: Two New Eimerians (Apicomplexa) from Insectivorous Mammals in Madagascar. Journal of Parasitology 97 (2), 2011, pp. 293-296
  38. ↑ Erwan Lagadec, Yann Gomard, Gildas Le Minter, Colette Cordonin, Eric Cardinale, Beza Ramasindrazana, Muriel Dietrich, Steven M Goodman, Pablo Tortosa and Koussay Dellagi: Identification of Tenrec ecaudatus, a Wild Mammal Introduced to Mayotte Island, as a Reservoir of the Newly Identified Human Pathogenic Leptospira mayottensis. PLoS Neglected Tropical Diseases 10 (8), 2016, p. E0004933. doi: 10.1371 / journal.pntd.0004933
  39. ↑ a b c Kathryn M. Everson, Voahangy Soarimalala, Steven M. Goodman and Link E. Olson: Multiple loci and complete taxonomic sampling resolve the phylogeny and biogeographic history of tenrecs (Mammalia: Tenrecidae) and reveal higher speciation rates in Madagascar's humid forests . Systematic Biology 65 (5), 2016, pp. 890-909 doi: 10.1093 / sysbio / syw034
  40. ↑ Link E. Olson and Steven M. Goodman: Phylogeny and biogeography of tenrecs. In: Steven M. Goodman and Jonathan P. Benstead (Eds.): The natural history of Madagascar. University of Chicago Press, 2003, pp. 1235-1242
  41. ^ Matjaž Kuntner, Laura J. May-Collado and Ingi Agnarsson: Phylogeny and conservation priorities of afrotherian mammals (Afrotheria, Mammalia). Zoologica Scripta 40 (1), 2011, pp. 1-15
  42. ^ Henri Heim de Balsac: Insectivores. In: R. Battistini and G. Richard-Vindard (eds.): Biogeography and ecology in Madagascar. The Hague, 1972, pp. 629-660
  43. ^ A b Don E. Wilson and DeeAnn M. Reeder: Mammal Species of the World. A taxonomic and geographic Reference. Johns Hopkins University Press, 2005 ( [5] )
  44. ↑ Étienne de Flacourt: Histoire de la grande isle Madagascar. Paris, 1661, pp. 1–471 (p. 152) ( [6] )
  45. ↑ Georges-Louis Leclerc de Buffon: Histoire naturelle, générale et particulière. , Tome Douzième. Paris, 1764, pp. 440–441, p. 450 and plate 56 ( [7] )
  46. ↑ a b c Fredericus Anna Jentink: On the hedgehogs from Madagascar. Notes from the Royal Zoological Museum at Leyden 1879, pp. 137–151 ( [8] )
  47. ↑ Johann Christian Daniel Schreber: The mammals in illustrations according to nature with descriptions. Third part. Erlangen, 1777, p. 584 ( [9] ) and volume 1, panel 165 ( [10] )
  48. ↑ Georges Cuvier: Tableau elementaire de l'histoire naturelle des animaux. Paris, 1798, pp. 1–710 (108) ( [11] )
  49. ^ Bernard Germain Lacépède: Tableau des divisions, sous-divisoins, ordres et genres des mammifères. Paris, 1799; Reprinted in the Memoirs de l'Institut national des sciences et arts 3, 1801, pp. 489–519 (p. 492) ( [12] )
  50. ^ Johann Karl Wilhelm Illiger: Prodromus systematis mammalium et avium additis terminis zoographicis utriudque classis. Berlin, 1811, pp. 1–301 (p. 124) ( [13] )
  51. ^ Georges Cuvier: Le règne animal distribué d'après son organization. Paris, 1817, pp. 1–540 (p. 166) ( [14] )
  52. ^ A b c Etienne Geoffroy Saint-Hilaire: Tanrec. Cuv. Centetes. Illig. et Éricule. Ericulus. Is. Geoff. Magasin de Zoologie Serie 2 1, 1839, pp. 1–37 ( [15] )
  53. ^ Anselme Gaëtan Desmarest: Mammalogie, ou, Description des espèces de mammifères. Paris, 1820, pp. 1–276 (p. 162) ( [16] )
  54. ↑ Andrew W. Murray: The geographic distribution of mammals. London, 1866, pp. 1–420 (p. XIV) ( [17] )
  55. ^ Charles Lucien Jules Laurent Bonaparte: Synopsis vertebratorum systematis. Nuovi Annali delle Scienze Naturali 2, 1838, pp. 105-133 ( [18] )
  56. ↑ George Gaylord Simpson: The principles of classification and a classification of mammals. Bulletin of the American Museum of Natural History 85, 1945, pp. 1–350 (pp. 50 and 175–179)
  57. ↑ George Shaw: General Zoology. Vol. 1 London, 1800, pp. 1–552 (p. 548) ( [19] )
  58. ↑ Étienne Geoffroy Saint-Hilaire: Notice sur les mammiferes épineux de Madagascar. Comptes rendus hebdomadaires des séances de l'Académie des sciences 5, 1837, pp. 372–374 ( [20] )
  59. ^ Pieter Boddaert: Elenchus animalium. Rotterdam, 1785, p. 1.174 (p. 129) ( [21] )
  60. ^ A b Kathleen M. Muldoon, Donald D. de Blieux, Elwyn L. Simons, and Prithijit S. Chatrath: The Subfossil Occurrence and Paleoecological Significance of Small Mammals at Ankilitelo Cave, Southwestern Madagascar. Journal of Mammalogy 90 (5), 2009, pp. 1111-1131
  61. ^ A b D. A. Burney, N. Vasey, LR Godfrey, Ramilisonina, WL Jungers, M. Ramarolahy and L. Raharivony: New Findings at Andrahomana Cave, Southeastern Madagascar. Journal of Cave and Karst Studies 70 (1), 2008, pp. 13-24
  62. ↑ Steven M. Goodman and William L. Jungers: Extinct Madagascar. Picturing the island's past. University of Chicago Press, 2014, pp. 1–206 (pp. 65–73 and 94–101)
  63. ^ JU Ganzhorn, AW Ganzhorn, J.-P. Abraham, L. Andriamanarivo and A. Ramananjatovo: The impact of selective logging on forest structure and tenrec populations in western Madagascar. Oecologia 84, 1990, pp. 126-133
  64. ↑ Julia PG Jones, M. Mijasoa Andriamarovololona and Neal Hockley: The Importance of Taboos and Social Norms to Conservation in Madagascar. Conservation Biology 22 (4), 2008, pp. 976-986
  65. ↑ Kim E. Reuter and Brent J. Sewall: Taboos and sustainability of tenrec hunting in Madagascar. Afrotherian Conservation 12, 2016, pp. 11–15
  66. ^ Zoo animal list ( [22] ); last accessed on May 6, 2017

Web links

Commons : Large tenrek  album with pictures, videos and audio files