Grandidier-Kleintenrek
| Grandidier-Kleintenrek | ||||||||||||
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| Microgale grandidieri | ||||||||||||
| Olson , Rakotomalala , Hildebrandt , Lanier , Raxworthy & Goodman , 2009 |
The Grandidier Kleintenrek ( Microgale grandidieri ) is a species of mammal from the genus Kleintenreks within the Tenreks family . It is widespread in the western and southwestern part of Madagascar and inhabits dry forests and shrubbery there. The animals belong to the medium-sized representatives of the Kleintenreks. They have a strong body with agouti-like fur pattern, a strikingly short tail and an elongated head with a narrow snout. Little is known about the way of life. The species was scientifically introduced in 2009 and its population is not considered endangered.
features
Habitus
The Grandidier-Kleintenrek reaches a head-trunk length of 6.0 to 7.7 cm and a tail length of 3.3 to 3.7 cm. The tail thus takes up about a third to half the length of the rest of the body, which is significantly shorter than that of most other small tenreks. The body weight varies from 8.1 to 9.6 g. Overall, the Grandidier-Kleintenrek is a medium-sized representative of the Kleintenreks. In terms of physique, it corresponds to the other members of the genus with a spindle-shaped body, short and strong legs and an elongated and narrow head. The fur on the back is relatively fine and soft. It has a dark brown color mixed with a lighter brown, which creates an agouti- like coat pattern. The hair bases are mostly gray in color. On the underside, the fur is much finer and uniformly gray. The transition from the back to the peritoneum is indicated by a conspicuous line on the sides. The vibrissae are colored black. They are 15 mm long in the area of the mouth and 8 mm long at the nose. The ears are comparatively short with a length of 12 to 14 mm. They are characterized by a very fine, dark to black-brown fur on the inside and outside. The tops of the hands and feet are sparsely hairy, the fur is brown here. Both the hands and the feet each have five rays. With a length of 11 to 13 mm, the foot is also short compared to other Kleintenreks. The rays II and IV are almost the same length, the inner ray, however, is only half as long as the second, the outer reaches about two thirds of the length of the fourth. On the undersides of the hands and feet, there are small pads between the fingers and the roots of the toes. The hypothenar and thenar pads are reduced in size.
Skull and dentition features
The greatest length of the skull varies from 20.2 to 21.9 mm, while the width of the skull is 8.7 to 8.9 mm. Overall, the skull shows an elongated and narrow structure. The rostrum , however, is rather short and takes up only a third of the entire length of the skull, it ends in a pointed tip. The forehead line is straight, but there is no stronger constriction behind the eyes when viewed from above. On the parietal bone, there is only a weakly developed parietal ridge , and the bulge on the occiput is only slightly developed. As with all tenreks, the zygomatic arch is not closed, the front arch section ends bluntly in contrast to the wing-like termination in the closely related short-tailed small tenrek ( Microgale brevicaudata ). The basic phenoid is significantly more sculptured and extended than this one.
The lower jaw has a slender shape, the crown process points backwards, the angular process is relatively long. The dentition has the typical, slightly reduced number of teeth of the other Kleintenreks. The dental formula is: . The rows of teeth run almost parallel to each other with a slight convergence in the front and a slight divergence in the rear. In the short-tailed Kleintenreks, on the other hand, the rear teeth are pushed further apart. The first and third incisors in the upper dentition each have two cusps ( bicuspid ), the middle three ( tricuspid ). The size of the cutting teeth decreases towards the rear, the second incisor is the largest in the lower jaw. In contrast to the lower incisors, the upper incisors are not closed. The canine is relatively large both above and below, but it is not designed as dagger-like as in the short-tailed small tenrek. Also deviating from this, there are no conspicuous diastemas between the premolars in the upper jaw . The molars generally have a zalambdodontic structure with three clearly pronounced cusps on the chewing surfaces. In the upper jaw, the last premolar is larger than the molar, and the third molar is greatly reduced in size. In contrast, the last premolar and the three molars in the lower jaw are almost the same size. The length of the upper row of teeth is 9.3 to 10 mm.
distribution
The Grandidier-Kleintenrek occurs in western and southwestern Madagascar in the provinces of Toliara and Mahajanga . In Toliara, the species is documented from eight different sites with around two dozen individuals. The find locations extend from the Namoroka massif in the north south to the north bank of the Onilahy River in the south-west. From Mahajanga only one site from the Forêt de Beanka near Maintirano in the south has been reported, from here about 20 individuals are known. Overall, the animals could be detected in three different forest types in the area of distribution: in dry, deciduous forests with limestone rocks (such as Andriabe, Andranogidro, Beanka, Bendrao or Ankidrodroa), in transition areas from similar forests to thorny bush landscapes with heights of 6 to 8 m (approx Fiherenana) and in gallery forests interspersed with tamarind and fig trees and surrounded by thorn bush areas (e.g. Sept Lacs and Antafiky). The climate is rather dry with annual rainfall of 350 to 410 mm, sometimes droughts occur. The height distribution ranges from 50 to 430 m. In the Forêt de Beanka , the Grandidier-Kleintenrek appears sympathetically with the short-tailed Kleintenrek. Another deposit that has not yet been verified with certainty could exist near Morondava in the north of the Toliara province.
Way of life
The way of life of the Grandidier Kleintenreks has hardly been researched. Field studies in 2001 and 2002 suggest that the animals are seasonally active, as no individuals have been caught in the dry season. It is possible that the animals hibernate or hibernate during this phase of the reduced food supply. So far, no special fat storage in the tail has been observed, as is known from the Dobsonian Kleintenrek ( Nesogale dobsoni ).
Systematics
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Internal systematics of the Kleintenreks according to Everson et al. 2016
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Gran Didier-Kleintenrek is a kind from the genus of microgale ( Microgale ) within the family of tenrecs (Tenrecidae). Together with the rice burrowers ( Oryzorictes ) and the representatives of the genus Nesogale , the Kleintenreks form the subfamily of the Reistenreks (Oryzorictinae). With more than 20 species, the Kleintenreks are the most diverse in shape and, due to some morphological features, also the most original member of the family. The genus was formed in the Lower Miocene around 16.8 million years ago and has diversified considerably in the period that followed. Today's representatives have adapted to different ways of life, ranging from partly underground digging to above-ground living to tree-climbing and water-dwelling variants. A large part of the Kleintenreks inhabit the humid forests of eastern Madagascar, a few species are also found in the drier landscapes of the western part of the island. Various kinship groups can be identified within the genus. The Grandidier Kleintenrek is morphologically and molecularly genetically most closely related to the Short-tailed Kleintenrek ( Microgale brevicaudata ). The genetic distance between the two species is around 14.5 to 18.8%, which is roughly the same as that of other sister taxa within the Kleintenreks.
The first scientific description of the Grandidier Kleintenreks was made in 2009 by Link E. Olson and research colleagues. They had almost two dozen individuals from various sites in western and southwestern Madagascar at their disposal. The holotype comprises a fully grown female 11.1 cm total length and 9.1 g weight. It comes from Antafiky on the northern bank of the Onilahy River in the southwest of the island, which is considered a type region. Some of the individuals were collected during several scientific expeditions in 2001 and 2002; the holotype was found on February 28, 2002. The specific epithet grandidieri honors Alfred Grandidier , a French naturalist who, at the turn of the 19th and 20th Century as one of the first explorers to explore the rich fauna of Madagascar.
Threat and protection
The IUCN classifies the Grandidier-Kleintenrek as "not threatened" ( least concern ). The species is difficult to observe, but the animals apparently also get along in landscapes that are more dominated by humans, especially areas with pasture farming, tree felling for timber removal and seasonal agriculture. In the north of the distribution area, the Grandidier-Kleintenrek occurs in several nature reserves, for example in the Namoroka National Park , in the Bemaraha National Park as well as in the Menabe-Antimena reserve north of Morondava. In contrast, the southern populations are not yet present in protected areas. In principle, more intensive observation of the species is necessary, mainly in view of the greater anthropogenic influence on the southern distribution area.
literature
- 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. 171) ISBN 978-84-16728-08-4
- Link E. Olson, Z. Rakotomalala, KBP Hildebrandt, HC Lanier, Christopher J. Raxworthy and Steven M. Goodman: Phylogeography of Microgale brevicaudata (Tenrecidae) and description of a new species from Western Madagascar. Journal of Mammalogy 90 (5), 2009, pp. 1095-1110
Individual evidence
- ↑ a b c d e f g h Link E. Olson, Z. Rakotomalala, KBP Hildebrandt, HC Lanier, Christopher J. Raxworthy and Steven M. Goodman: Phylogeography of Microgale brevicaudata (Tenrecidae) and description of a new species from Western Madagascar . Journal of Mammalogy 90 (5), 2009, pp. 1095-1110
- ↑ a b c 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. 171) ISBN 978-84-16728-08-4
- ↑ Steven M. Goodman, Haridas H. Zafindranoro and Voahangy Soarimalala: A case of the sympatric occurrence of Microgale brevicaudata and M. grandidieri (Afrosoricida, Tenrecidae) in the Beanka Forest, Maintirano. Malagasy Nature 5, 2011, pp. 104-108
- ↑ Voahangy Soarimalala, Haridas H. Zafindranoro and Steven M. Goodman: Diversité des petits mammifères sur une formation de tsingy: cas de la forêt de Beanka, Région Melaky, Ouest de Madagascar. Malagasy Nature 7, 2013, pp. 245-258
- ^ A b P. J. Stephenson, Voahangy Soarimalala and Steven M. Goodman: Microgale grandidieri. The IUCN Red List of Threatened Species 2015. e.T54008309A54008345 ( [1] ); last accessed on June 26, 2016
- ↑ a b Voahangy Soarimalala: Les Afrosoricides de la forêt sèche malgache. Afrotherian Conservation 8, 2011, pp. 4-9
- ↑ 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
- ^ JF Eisenberg and Edwin Gould: The Tenrecs: A Study in Mammalian Behavior and Evolution. Smithsonian Institution Press, 1970, pp. 1-138
- ^ RDE MacPhee: The Shrew Tenrecs of Madagascar: Systematic Revision and Holocene Distribution of Microgale (Tenrecidae, Insectivora). American Museum Novitates 2889, 1987, pp. 1-45
- ↑ Martin Nicoll and Nanie Ratsifandrihamanana: The growth of Madagascar's protected areas system and its implications for tenrecs (Afrosoricida, Tenrecidae). Afrotherian Conservation 10, 2014, pp. 4-8
Web links
- Microgale grandidieri in the endangered Red List species the IUCN 2016 Posted by: PJ Stephenson, Voahangy Soarimalala and Steven M. Goodman, 2014. Accessed on 26/06/2016.