Gnome lesser rek

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Gnome lesser rek
Systematics
without rank: Afroinsectiphilia
Order : Tenrecus (Afrosoricida)
Family : Tenreks (Tenrecidae)
Subfamily : Travel treks (Oryzorictinae)
Genre : Kleintenreks ( Microgale )
Type : Gnome lesser rek
Scientific name
Microgale pusilla
Major , 1896

The Gnomkleintenrek ( Microgale pusilla ), also called Madagascar-Kleintenrek or Madagascar-Kleintanrek , is a species of mammal belonging to the genus Kleintenreks within the Tenrek family . In addition to the dwarf lesser trek, it is one of the smallest representatives of the lesser tenreks. Like all members of the genus, the animals have a spindle-shaped body with strong limbs and a long, narrow head that tapers at the front. The tail becomes a little longer than the rest of the body. The distribution area includes central and southeastern Madagascar . Here the gnome lesser rek occurs in tropical rainforests , unlike numerous other lesser reek , it also inhabits more open or human-shaped landscapes. The way of life of the animals is largely unexplored, insects serve as food . The species was scientifically introduced in 1896 and its population is considered safe.

features

Habitus

The Gnomleintenrek is the smallest representative of the genus next to the dwarfleintenrek ( Microgale parvula ). The total length is between 12.1 and 14.6 cm after ten measured individuals from several areas of the distribution area. The head-trunk length is 5.1 to 6.2 cm and the tail length is 6.1 to 8.5 cm. The body weights of a dozen animals examined varied from 2.6 to 3.9 g. For seven other individuals total lengths of 11.9 to 13.6 cm, body lengths of 4.7 to 5.6 cm, tail lengths of 6.5 to 7.7 cm and a body weight of 3.1 to 4.2 g are given . Like all Kleintenreks, the Gnome Kleintenrek is characterized by a spindle-shaped body with short and strong limbs and a long, narrow and pointed head. The ears are 10 to 13 mm long. The back fur is light to reddish brown in color, the underside has a paler tint. The transition from the fur color of the back to the underside is moderately abrupt on the sides. The tail is slightly longer than the rest of the body. It has a dark brown tint on the top and a slightly lighter tint on the underside. The hands and feet each have five clawed rays, the rear foot measures 11 to 14 mm in length.

Skull and dentition features

The greatest length of the skull varies from 15.7 to 18.0 mm, the values ​​for the greatest width on the brain skull are 6.0 to 7.1 mm, on the incompletely formed zygomatic arches it is 5.6 to 6.1 mm mm only slightly narrower. The anterior arch section of the zygomatic arch begins approximately above the first molar and takes up the length of the entire molar row, which is comparatively long. The rostrum is built relatively short and graceful, the back skull bulges clearly. The lower jaw is 9.5 to 11.4 mm long and 3.6 to 4.0 mm high on the crown process. The bit is made as with the other microgale of 40 teeth together and has the following dental formula : . In the upper dentition, the second and third incisors are close together, but are separated from the neighboring teeth by short diastemas . The anterior lower premolar (P2) resembles a canine tooth ( canin-shaped ) and therefore has only one root, and the additional cusps on the tooth crown are rather small. The premolars increase in size from front to back, in the lower jaw the rearmost (P4) exceeds the preceding (P3) by 60%, in the upper jaw it is 20%. The molars correspond to those of the other Kleintenreks and have a zalambdodontic occlusal surface pattern with three main cusps. The posterior upper molar is reduced in size. The entire upper row of teeth is 6.7 to 7.7 mm long.

distribution

Distribution area of ​​the gnome lesser rectum

The gnome lesser trek is an endemic inhabitant of Madagascar . Its distribution area extends in a more or less wide strip over the central and south-eastern areas of the island state. Significant sites are located in the central highlands, for example in the forest area of ​​Ambohitantely and Tsinjoarivo, all in the province of Antananarivo . Other find areas include the forest areas of Itremo and Manambolo and the forest area of ​​Vandrozo in the province of Fianarantsoa . The southernmost evidence is provided by the wet forests of Tolagnaro in the extreme southeast of the island in the province of Toliara . The animals are mainly found in tropical rainforests , but they can also be found at the edges of forests, in landscapes with fragmented forests, in marshland rich in sour grass , on agricultural areas such as rice fields and in unforested regions of eastern Madagascar. Sometimes individual individuals were observed up to 3 km away from forests. In contrast to numerous other Kleintenreks on the eastern part of the island, the Gnome Kleintenrek is not an indicator of undisturbed forests. The altitude ranges from 530 to 1670 m. The species can occur relatively frequently locally.

Way of life

The way of life of the gnome lesser rectum has hardly been researched. The animals inhabit forests, but also occur in open landscapes. According to isotope studies on individuals from the forest area of ​​Tsinjoarivo, they mainly feed on insects ; the very high δ15N content found in these analyzes suggests that they are largely specialized in predatory prey. Occasionally, individual animals were in Gewöllen the Barn Owl proven. The Fanaloka appears as another predator .

Systematics

Internal systematics of the Kleintenreks according to Everson et al. 2016
 Microgale  



 Microgale pusilla


   

 Microgale majori


   

 Microgale principula


   

 Microgale jenkinsae


   

 Microgale longicaudata






   

 Microgale mergulus


   

 Microgale parvula




   



 Microgale brevicaudata


   

 Microgale grandidieri



   

 Microgale drouhardi


   

 Microgale monticola


   

 Microgale taiva





   



 Microgale gracilis


   

 Microgale thomasi


   

 Microgale cowani


   

 Microgale jobihely





   

 Microgale dryas


   

 Microgale gymnorhyncha




   

 Microgale soricoides


   

 Microgale fotsifotsy


   

 Microgale nasoloi







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The Gnomkleintenrek is a kind from the genus of microgale ( Microgale ) within the family of tenrecs (Tenrecidae). The Kleintenreks also form together with the rice burrowers ( Oryzorictes ) and the representatives of the genus Nesogale the subfamily of the Reistenreks (Oryzorictinae). In addition, with more than 20 species, they represent the most diverse member of the Tenreks. According to some morphological features, they can be regarded as more originally within the family. According to molecular genetic studies, the genus originated in the Lower Miocene around 16.8 million years ago and split up many times in the following time. Today's Kleintenreks have adapted to different ways of life, so there are species that sometimes dig underground, live above ground, or tree-climb and inhabit water. The majority of the known representatives live in the humid forests of eastern Madagascar, a few also occur in the drier landscapes of the western part of the island. Within the genus, different kinship groups can be distinguished both morphologically and genetically. In both approaches, a closer grouping with the long-tailed small tenreks such as the large ( Microgale principula ) and the small long-tailed small tenrek ( Microgale longicaudata ) emerges. There is no closer relationship to the similarly sized dwarf shrimp ( Microgale parvula ). Both forms can be distinguished by the color of their fur, the proportional length of the tail and some features of the skull and teeth.

The Gnomleintenrek was first described scientifically in 1896 by Charles Immanuel Forsyth Major . The holotype includes a fully grown male that has a head-to-trunk length of 5.3 cm and a tail length of 7.4 cm. According to Major's information in the first description, this comes from the area around Vinanitelo, a mountain ridge that reaches a height of 1290 m above sea level and is 50 km southeast of Fianarantsoa and 10 km south-southeast of Vohitrafeno . The specimen copy had been collected there by Major himself in the year of the first description. For a long time, the entire region was considered to be the type area of ​​the species, since the original label of the holotype also includes the place name Ambohimanana, a village near the ridge, Paulina D. Jenkins limited the type locality to this in 2005. In addition to the holotype individual, Major named a cave near Antsirabe ("Sirabè") in the central Madagascan region of Vàkinankàratra as a further distribution area of ​​the species. The specific epithet pusilla is of Latin origin and means "small", it thus refers to the size of the animals, who at that time represented the smallest representatives of the Kleintenreks.

Subspecies of the gnome lesser rectum are not known. There are isolated subfossil finds. These include remains from the Andrahomana Cave , which is embedded in Eolianite outcrops on the cliff southwest of Tolagnaro in the extreme southeast of Madagascar. The cave, which has been investigated since the end of the 19th century, is located in a transition area from the arid regions of the western to the wetlands of the eastern part of the island. Today the region no longer belongs to the immediate distribution area of ​​the gnome lesser rectum, but the species occurs in the neighboring damp forests. The extremely rich fossil material covers the period of the last 8,700 years, in addition to the gnome lesser rectum, bone remnants including the short-tailed ( Microgale brevicaudata ) and the lesser long-tailed lesser ternrek have been discovered here. Other finds come from Lelia and Anjohimpaty in the area of ​​today's Tsimanampetsotsa National Park in the south-western dry area of ​​the island. The landscape here is characterized by thorny bushes on a limestone underground. Parts of the teeth and mandible were found that are associated with owl wool of unknown age. These sites are also outside the current range of the species. Allocation to Madagascar.Kleintenrek, as originally assumed, is now partly doubted, since in this region with the Jenkins-Kleintenrek ( Microgale jenkinsae ) only a slightly larger species occurs in this region . In terms of its tooth features, such as the single-rooted anterior mandibular premolar, this has similarities to the Gnome Kleintenrek.

Threat and protection

Overall, the gnome lesser trek is widespread in the forest landscapes of eastern Madagascar, and the population is assumed to be correspondingly large. In addition, the species is also found on the edges of forests and in human-influenced landscapes including rice fields and thus shows a great adaptability. Strong local changes in the landscape or bush and forest fires can be viewed as greater threats. For these reasons, the IUCN classifies the species as “not threatened” (least concern) . So far, the gnome reek has been detected in three protected areas, in the Mantadia Andasibe National Park as well as in the Ambohitantely nature reserve and the Analamazaotra nature reserve . Field studies of its ecology and habitat are important for the conservation of the species.

literature

  • Charles Immanuel Forsyth Major: Description of four additional new mammals from Madagascar. The Annals and magazine of natural history 18, 1896, pp. 461–463 ( [2] )
  • 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 (pp. 171–172) ISBN 978-84-16728-08-4

Individual evidence

  1. ↑ a b c d e f g R. DE MacPhee: The Shrew Tenrecs of Madagascar: Systematic Revision and Holocene Distribution of Microgale (Tenrecidae, Insectivora). American Museum Novitates 2889, 1987, pp. 1-45
  2. ↑ a b c Steven M. Goodman, Paulina D. Jenkins and Olivier Langrand: Exceptional records of Microgale species (Insectivore: Tenrecidae) in vertebrate food remains. Bonn zoological contributions 47 (1/2), 1997, pp. 135-138
  3. ↑ a b c d e Steven M. Goodman and Voahangy Soarimalala: A new species of Microgale (Lipotyphla: Tenrecidae: Oryzorictinae) from the Forêt des Mikea of ​​southwestern Madagascar. Proceedings of the Biological Society of Washington 117 (3), 2004, pp. 251-265
  4. ^ A b Charles Immanuel Forsyth Major: Description of four additional new mammals from Madagascar. The Annals and magazine of natural history 18, 1896, pp. 461-463
  5. ^ A b Paulina D. Jenkins, Christopher J. Raxworthy and Ronald A. Nussbaum: A new species of Microgale (Insectivora, Tenrecidae), with comments on the status of four other taxa of shrew tenrecs. Bulletin of the Natural History Museum of London (Zoology) 63 (1), 1997, pp. 1-12
  6. ↑ a b 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 (pp. 171–172) ISBN 978-84-16728-08-4
  7. ↑ Paulina D. Jenkins: A New Species of Microgale (Insectivora: Tenrecidae) from Northeastern Madagascar. American Museum Novitates 2910, 1988, pp. 1-7
  8. ↑ PJ Stephenson, H. Randriamahazo, N. Rakotoarison and PA Racey: Conservation of mammalian species diversity in Ambohitantely Special Reserve, Madagascar. Biological Conservation 69, 1994, pp. 213-218
  9. ↑ Steven M. Goodman and Daniel Rakotondravony: The effects of forest fragmentation and isolation on insectivorous small mammals (Lipotyphla) on the Central High Plateau of Madagascar. Journal of Zoology London 250, 2000, pp. 193-200
  10. ↑ Steven M. Goodman, Daniel Rakotondravony, Marie Jeanne Raherilalao, Domoina Rakotomalala, Achille P. Raselimanana, Voahangy Soarimalala, Jean-Marc Duplantier, Jean-Bernard Duchemin and J. Rafanomezantsoa: Inventaire biologique de la Foret de Tsinjoarivo, Ambatolampy. Akon'ny Ala 27, 2000, pp. 18-27
  11. ↑ a b Link E. Olson, Steven M. Goodman and Anne D. Yoder: Illumination of cryptic species boundaries in long-tailed shrew tenrecs (Mammalia: Tenrecidae; Microgale), with new insights into geographic variation and distributional constraints. Biological Journal of the Linnean Society 83, 2004, pp. 1-22
  12. ^ A b Steven M. Goodman, FJ Kerridge and RC Ralisomalala: A note on the diet of Fossa fossana (Carnivora) in the central eastern humid forests of Madagascar. Mammalia 67 (4), 2003, pp. 595-598
  13. ↑ Vonjy Andrianjiakarivelo, Emilienne Razafimahatratra, Yvette Razafindrakoto and Steven M. Goodman: The terrestrial small mammals of the Parc National de Masoala, northeastern Madagascar. Acta Theriologica 50 (4), 2005, pp. 537-549
  14. ^ Daniel Rakotondravony, Steven M. Goodman, Jean-Marc Duplantier and Voahangy Soarimalala: Les petits mammifères. In: J. Ratsirarson and Steven M. Goodman (eds.): Dans Inventaire biologique de la forêt littorale de Tampolo (Fenoarivo Atsinanana). Center d'Information et de Documentation Scientifique et Technique, Antananarivo, Recherches pour le Développement, Série Sciences biologiques 14, 1998, pp. 197-212
  15. ↑ Toky M. Randriamoria, Voahangy Soarimalala and Steven M. Goodman: Terrestrial “forest-dwelling” endemic small mammals captured outside of natural habitats in the Moramanga District, central eastern Madagascar. Malagasy Nature 9, 2015, pp. 97-106
  16. ↑ a b c P. J. Stephenson, Voahangy Soarimalala and Steven M. Goodman: Microgale pusilla. The IUCN Red List of Threatened Species 2016. e.T41314A97201685 ( [1] ); last accessed on October 29, 2016
  17. ↑ Melanie Dammhahn, Voahangy Soarimalala and Steven M. Goodman: Trophic Niche Differentiation and Microhabitat Utilization in a Species-rich Montane Forest Small Mammal Community of Eastern Madagascar. Biotropica 45 (1), 2013, pp. 111-118
  18. ↑ 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
  19. ^ JF Eisenberg and Edwin Gould: The Tenrecs: A Study in Mammalian Behavior and Evolution. Smithsonian Institution Press, 1970, pp. 1-138
  20. ^ Paulina D. Jenkins and Michael. D. Carleton: Charles Immanuel Forsyth Major's expedition to Madagascar, 1894 to 1896: beginnings of modern systematic study of the island's mammalian fauna. Journal of Natural History 39 (20), 2005, pp. 1779-1818
  21. ^ DA 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
  22. ^ A b 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 79–86)

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