Temminck bare-tailed pouch rat
| Temminck bare-tailed pouch rat | ||||||||||||
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| Metachirus myosuros | ||||||||||||
| ( Temminck , 1824) |
The Temminck nudibranch rat ( Metachirus myosuros ) is a species of bag mammal from the nudibranch rat genus . It occurs from southern Nicaragua through Colombia and the western and southern Amazon basins to southeastern Brazil. There is also an isolated population in Chiapas in southern Mexico.
description
The Temminck bare-tailed pouch rat is colored red-brown, yellow-brown or gray-brown on the back, while the belly is brown to yellowish-white. The males reach a head trunk length of 21.7 to 28.5 cm, have a 25.6 to 33.6 cm long tail, 40 to 47 mm long hind feet, 30 to 39 mm long ears and reach a weight of 248 to 485 g . Females stay smaller with a head rump length of 21.8 to 27.8 cm, a 26.5 to 33.6 cm long tail and a weight of 270 to 430 g. Their hind feet reach a length of 37 to 46 mm and the ears are 30 to 39 mm long. The Temminck nudibranch rat is thus somewhat smaller than Metachirus nudicaudatus , the second species of nudibranch rat. The two outwardly very similar species can be distinguished primarily on the basis of their skull morphology. Large, older males of both species develop a two-part crest consisting of a right and left section . Both parts of the crest converge on the rear of the skull in the Temminck nudibranch rat, while in Metachirus nudicaudatus they remain separate. The rostrum (snout) is more strongly developed in the Temminck bare- tailed pouch rat and the zygomatic arches are more rounded than in M. nudicaudatus . The palate windows are shorter and narrower in the Temminck bare-tailed rat than in M. nudicaudatus . Nakedtail pouch rats are the largest pouch rats whose females have no pouches, but only a hairless brood spot with nine teats, four on each side and one in the middle. The size and shape of the skull are different in males and females. The tail of the animals is hairless from base to tip.
Way of life
The Temminck nudibranch rat occurs from sea level to altitudes of 2100 meters, mainly in various forests, but has also been found on farms, in orchards or in villages. The animals are nocturnal, terrestrial (ground dwelling) and good runners. In southeastern Brazil 50 to 600 specimens per km² were counted while in the Restinga , a landscape form with forests on sandy-loamy soils, only 22 individuals live per km². The animals feed mainly on insects. Faecal samples from the Restinga mainly contained the remains of ants, termites, cockroaches and beetles, as well as seeds from cacti and nightshade plants. The fruits of palm trees and bromeliads are also eaten in the Atlantic rainforest , as are hymenoptera , spiders, bed bugs, cicadas, birds, small mammals and lizards. In Chiapas, the shells of bird eggs were also found in the droppings, and in the gallery forests of the Cerrado , a third of the excretions contained seeds from bushes or trees, especially from Clidemia and Miconia species. In the Amazon basin, the Temminck nudibranch rat is likely to breed year-round. The gestation period is 21 days and the number of young animals is between four and nine. After birth, the young animals suck on the teats and stay there for a period of 75 to 80 days. After that, the females leave them alone in the nest when they go looking for food. It takes 30 to 45 days until weaning and after about 130 days the young animals are completely independent. They are sexually mature at 10 months of age.
Systematics
The Temminck nudibranch rat was first scientifically described in 1824 by the Dutch zoologist Coenraad Jacob Temminck . Together with all other species of bare-tailed rats , it was later synonymous with Metachirus nudicaudatus and M. nudicaudatus was long considered the only one of the genus Metachirus monotypical . In the marsupial volume of the Handbook of the Mammals of the World , published in June 2015, Metachirus nudicaudatus was described as the only species with five subspecies:
- Metachirus nudicaudatus nudicaudatus , Venezuela south of the Orinoco , the three Guayanas and northern Brazil
- Metachirus nudicaudatus colombianus , Chiapas , Central America, western and northern Colombia, Venezuela west of Lake Maracaibo, and western Llanos and the northwest of Ecuador
- Metachirus nudicaudatus modestus , southern Brazil, east and central Paraguay, and the Argentine provinces of Misiones and Formosa
- Metachirus nudicaudatus myosuros , eastern Brazil from Pernambuco to Santa Catarina
- Metachirus nudicaudatus tschudii western Amazon basin, d. H. Southeast Colombia, West Brazil, East Peru, and North and East Bolivia
However, the authors note that it is likely that the genus contains more than one species, as there are large genetic differences between the nudibranch pouch rats from different regions. In June 2019, the pouch rat expert Robert S. Voss and two other biologists therefore divided the bare tail pouch rats into two species. The populations of nudibranch rats found in northeastern South America, which have a basal position in the Metachirus family tree, are becoming an independent species that is given the name Metachirus nudicaudatus , as the terra typica of Metachirus nudicaudatus is in French Guiana . All other populations and subspecies are grouped together under the name Metachirus myosuros .
The relationships within the bare-tailed pouch rats according to Voss et al .:
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supporting documents
- ↑ a b c d e Diego Astúa: Family Didelphidae (Opossums). Pages 70-186 in Don E. Wilson , Russell A. Mittermeier : Handbook of the Mammals of the World - Volume 5. Monotremes and Marsupials. Lynx Editions, 2015, ISBN 978-84-96553-99-6 , page 157.
- ^ A b c d Robert S. Voss, David W. Fleck and Sharon A. Jansa: Mammalian Diversity and Matses Ethnomammalogy in Amazonian Peru Part 3: Marsupials (Didelphimorphia). Bulletin of the American Museum of Natural History, 2019 (432): 1-90. doi: 10.1206 / 0003-0090.432.1.1 , pages 61-68.
- ^ Patton, JL and LP Costa. 2003. Molecular phylogeography and species limits in rainforest didelphid marsupials of South America. Page 66 and 68 in ME Jones, CR Dickman and M. Archer (editors), Predators with pouches: the biology of carnivorous marsupials. 63-81. Melbourne: CSIRO Press.