Elvira rock rat
| Elvira rock rat | ||||||||||
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| Systematics | ||||||||||
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| Scientific name | ||||||||||
| Cremnomys elvira | ||||||||||
| ( Ellerman , 1946) |
The Elvira rock rat ( Cremnomys elvira ) is a barely researched rodent species from the genus of Indian rock rats ( Cremnomys ). It was considered lost between its first description in 1946 and 2014.
features
The measurements are known only from two females described by Sir John Ellerman in 1946 . The head-torso lengths are 149 and 126 mm, the tail lengths 196 and 180 mm, the hind foot lengths 32 and 30 mm and the ear lengths 21 and 22 mm. The greatest lengths of the skull between the occiput and the nasal bone (occipitonasal length) are 41.1 and 38.2 mm, the palate lengths 20.5 and 18.9 mm, the diastema lengths 10.8 and 9.5 mm, the palatal hole lengths 9.1 and 7, 9 mm, the length of the tympanic membranes 5.9 and 5.6 mm and the lengths of the teeth in the upper jaw 6.1 and 5.9 mm. The skull is strongly fluted, the frontal bone is quite wide, the tympanic bladder makes up about 14 percent of the length of the skull, the palatal holes are very long and extend between the rows of teeth. The length of the palatine bone is less than half the length of the skull. The tail length is approximately 136 percent of the head-trunk length. The fifth back toe is quite long. Apparently there are six sole pads. The fur is brownish-gray on the top and greyish-white on the underside. The feet are white. The tail is two-colored. The female has three pairs of mammary glands.
Distribution area
The Elvira rock rat is endemic to the Eastern Ghats , the only evidence so far comes from the Kurumbapatti region in the Salem district in the Indian state of Tamil Nadu .
Habitat and way of life
The Elvira rock rat inhabits tropical semi-arid and dry deciduous forests and scrub. It occurs in rocky regions at altitudes between 230 and 380 m. Their way of life is nocturnal and their feet are adapted to digging. It prefers rocky outcrops and gaps in the rock that are surrounded by sparse grass, herbs and tall trees.
status
The IUCN lists the Elvira rock rat in the " critically endangered " category . The distribution area is very small at 100 km². During a four-month study between September and December 2014, twelve adult animals were discovered. There had previously been no evidence of the species since it was first described in 1946.
There was a qualitative and quantitative deterioration in habitat conditions at a rate of 20 to 50 percent between 2006 and 2016. A predicted rate is less than 20 percent over the next 20 years. The causes of the decline in the species are believed to be the expansion of human settlements, cutting trees for the collection of firewood, and changes in land use. The mining and deposition of debris on the foothills of the small hills on the tree line could cause severe habitat damage. Uncontrolled grazing in the rocky areas could also have a negative impact on the habitat.
literature
- John R. Ellerman: Further notes on two little-known Indian murine genera, and preliminary diagnosis of a new species of Rattus (subgenus Cremnomys) from the Eastern Ghats. Ann. Mag. Nat. Hist., 13, 1946: p. 207-208.
- VC Agrawal: Taxonomic Studies on Indian Muridae and Hystricidae (Mammalia: Rodentia). Records of the Zoological Survey of India, Occasional Paper 180, 2000: 1-177.
- JRB Alfred & S. Chakraborty: Endemic Mammals of India . Records of the Zoological Survey of India. Occasional Paper No. 201. Zoological Survey of India, Kolkata, 2002.
Web links
- Cremnomys elvira inthe IUCN Red List of Threatened Species 2016.3. Posted by: S. Molur and Ros Kinnerley, 2016. Retrieved December 16, 2016.