Long-tailed dwarf hamster
The long-tailed hamster ( Cricetulus longicaudatus ) is an entity belonging to the Grey dwarf hamsters type of hamster. From Armand David discovered in today's Inner Mongolia and in 1867 by Alphonse Milne -Edwards as Cricetus ( Cricetulus ) longicaudatus described, it is used in several subspecies of the north and the center of China, Mongolia, southern Siberia and the eastern Kazakhstan. He is not threatened.
Its body length is eight to fourteen inches. Additionally there is a four to five centimeters long tail. Upper hand, his coat is beige - yellow or dark - brownish- gray, the under side it is greyish - white. It is closely tied to Rocky Mountain regions, feeds mainly on plant seeds and sometimes insects and is nocturnal. His self -dug construction is simple and often he inhabits rock crevices or burrows of other animals. From March to September, he brings to the world in one to three litters of four to nine pups.
From the closely related Daurian dwarf hamsters, the long-tailed dwarf hamster differs by the absence of dorsal stripe and the longer tail, the horror dwarf hamster through dark ears with a bright edge and the two-colored tail. It can be distinguished by the skull from Daurian dwarf hamster by the flat or less arched parietal bone and barely developed, lateral bulges of the alveoli. From other species of the Grey dwarf hamster, it differs by the large bullae.
- 2.1 habitat, diet and predators
- 2.2 Construction, action space and activity times
- 2.3 Reproduction
- 4.1 Outer systematics
- 4.2 Internal systematics
- 4.3 nomenclature
Body characteristics
Body measurements and fur
The long-tailed dwarf hamster is small, about the size of the Daurian dwarf hamster or a little bigger. His tail is slender, long and clearly longer than the hind paws. The head -body length is usually 80 to 135 mm, tail length 35 to 48 millimeters, the Hinterfußlänge 15 to 21 millimeters, the ear length 15 to 20 mm and body weight 15 to 50 grams. The tail length usually makes at least 33 percent of the head-body length. To the south, however, it decreases. So it measures the north 35 to 46 percent of the head -body length, with copies of Hebei only about 30 mm and of the subspecies Cricetulus longicaudatus chiumalaiensis in Qinghai only 21 to 39 millimeters.
The fur is darker than the gray dwarf hamster. Upper hand, it is including the nose, the cheeks down to the eye and the ear, the back to the tail and the upper part of the upper arm and thigh beige - yellow or dark - brownish- gray. The underside is greyish - white at the base with greyish - black and white at the tip of hair. Rarely, the hair is completely white. Along the side of the body proceeds a sharp, almost horizontal line that is formed by the contrasting color of the top and bottom. Upper hand, the tail is dark, under hand, it is pure white. The paws are oberseits also pure white. On either side of the snout at base of whiskers a stain. The ear cups are inside and outside dark with a bright edge and sometimes with conspicuous white tips. In the neck and between the ears, the skin may be slightly darker by the many dark guard hairs. However, a distinct dorsal stripe does not exist. Young animals are ashen. Up on the heel, the soles are naked.
To the south, the fur on the upper side is usually brighter. Darkest is the northern subspecies Cricetulus longicaudatus kozhantschikovi. In Hebei, the nominate form is also much darker, especially in the lower part of the back. Here are long hairs with black tips between numerous mostly slate-colored and at the tips of light - yellow-brown hair. In some specimens a dark dorsal stripe indicates. On the side of the body and in a small area behind each ear, the slate-colored hair, which leads to a bright ocher - yellow brown color dominate. On the chest there is a distinct, yellow-brown tint. The subspecies Cricetulus longicaudatus chiumalaiensis is the upper side slightly darker.
The skull of the long-tailed dwarf hamster is low and the top slightly arched or almost flat. The muzzle is narrow and long. The nasal bones form a distinct notch in the side view in the area of suture nasofrontalis. The parietal bone is flatter than the Daurian dwarf hamsters and forms only thin appendages forward out. Supraorbital ridges are not present. The Gelenknorren Occipital not protrude rearwardly beyond it. The bullae are large, high and round. The incisor holes are long and go back to behind the front edge of the first upper molar tooth. The foramen interpterygoideum is deep and reaches forward to the third upper molar. The tips of the upper incisors have more backward than in Daurian dwarf hamster and the incisors are thinner than the gray dwarf hamster. The bulges on the sides of the premaxillary bone formed by the tooth sockets are hardly developed. The greatest length of the skull is usually 25 to 31 millimeters.
Allen ( 1940) are the greatest skull length of nine specimens of the nominate form, however, with 23.2 to 26.5 millimeters, the Basallänge with 20.0 to 22.6 millimeters, the Palatallänge with 10.8 to 12.5 millimeters, the zygomatic width 11.8 to 13.5 mm and the Mastoidbreite with 10.5 to 11.9 millimeters. It is the width of the molar teeth with 4.6 to 5.1 millimeters, the length of the upper jaw teeth of 3.3 to 3.8 millimeters and the length of the lower jaw teeth with 3.7 to 3.9 millimeters. The skull of Cricetulus longicaudatus chiumalaiensis with an average of 28.3 millimeters in length, slightly larger and the skull is longer, slightly flatter and has slight ridges on bones. The bullae are larger and somewhat bloated. According to Wang and Cheng (1973 ), the greatest length of skull 26.5 to 30.7 millimeters, the Palatallänge 12.3 to 15.2 millimeters, the Nasalialänge 9.5 to 12.1 millimeters, the zygomatic width from 13.4 to 15, 5 centimeters, the interorbital width 4.2 to 4.9 mm and the Mastoidbreite 10.8 to 12.0 millimeters. The length of the bullae is 5.2 to 5.9 mm and the length of upper molar series 4.1 to 4.5 millimeters.
Genetics
The number of chromosomes of the long-tailed dwarf hamster in a double set of chromosomes is 24 and the number of arms of the autosomes is 34 The X chromosome is subtelozentrisch and the Y chromosome is submetacentric.
Habitat and behavior
Habitat, diet and predators
The long-tailed dwarf hamster is a stenotopic nature and closely linked to Rocky Mountain regions. In the southern part of its range is its habitat from deserts, shrub land, forests and upland meadows. In addition, it is found in mountain steppes in semi-deserts, in the foothills and on the southern slopes of mountains where bluegrasses and shrubs to grow. Most commonly it is in the semi-deserts of the foothills and in low-lying grasslands up to an altitude of 1900 meters above sea level. It also inhabits undeveloped Artemisia - grass steppes and the edges of fields. Optimal habitats are the slopes of low ridges with a pending bedrock and adjacent accumulations of stones and rocks and ancient rocks that are overgrown with bushes. In Mongolia, it could also occur in rocky scree. In winter it can penetrate as moderately synanthropic species in rural buildings and temporary dwellings. In the desert areas of Shanxi westward across the Gobi, it is the most common type of horror dwarf hamsters.
It feeds mainly on seeds and sometimes insects. In case of 100 percent of captured animals with filled cheek pouches was plant material, but found only 26 percent of animal Handsome material. In Tuva were found in 74 percent of the animals, the seeds of pea shrubs, 53 percent of wheat, 37 percent of the tragacanth and to a completely negligible proportion insects and vegetative plant parts. In Buryatia were found in 40 percent of the animals cores of Faul trees, 32 percent of the seeds Labkräutern, at 21 percent of the loosestrife and 14 percent of the Knöterichen. The amount of the insects was insignificant and vegetative plant parts were missing. Up nagter Faulbaum cores were often in Buryatia next crevices heap found which are interpreted as waste from the pantry. The investment in inventories could also be observed in human care. In Tuva, this can include up to 12 kilograms.
In Shanxi, he is an important prey of little owl.
Construction, home range and activity times
The Build of the long-tailed dwarf hamster are flat, extend horizontally below the surface, and are often created under rocks. They contain pantries and lined with grass nests are arranged in groups and have three to six inputs. The corridors are two to three inches in diameter and up to three meters long. In addition to these simple, self-dug Building he often uses rock crevices or burrows of marmots. There the young are thrown and raised.
On the basis of cheek pouch contents could be determined that his action space can be measured by more than 200 meters. He is nocturnal.
Reproduction
The propagation time of the long-tailed dwarf hamster starts in March or April. In Daurien he raises for the first time about last March third. Pregnant females were caught in August and the breeding season will probably take on into September. Two litters a year are normal, but wintered animals may come on up to three litters and those born in the first litter of the year animals throw usually only once. The litter size is four to nine pups. The number of embryos or uterine scars were Flint ( 1966) at 36 captive animals three times with four, eight times with five, 14 times with six, six times with seven, four times with eight and one with one on. Thus, the long-tailed dwarf hamster remains as to its propagation intensity slightly behind other hamsters.
Dissemination and fossils
The distribution area of the long-tailed dwarf hamster stretches across the north and the center of China, the West and the center of Mongolia, southern Siberia and the eastern Kazakhstan. In China, he is in the north of Xinjiang, in Inner Mongolia, Hebei, Beijing, Tianjin, in northern Henan, Shanxi, Shaanxi, Ningxia, Gansu, Qinghai and Tibet. In Mongolia it is spread east until about 104 degrees east. He was recently discovered in the northern part of the Ikh - Nartiin - chuluu Conservancy in the Eastern Gobi. In Siberia he inhabits Tuva, the Sayan Mountains and the West Dauriens.
Fossils are not known.
Systematics and Nomenclature
Outer systematics
Molecular genetic studies of the mitochondrial cytochrome b and 12S rRNA genes and the nuclear vWF gene by Neumann and colleagues ( 2006) showed for the investigated hamster species is a sister group relationship of the long-tailed dwarf hamster with the Daurian dwarf hamsters. Accordingly, the two species have separated from other hamster species from each other and from 5.8 to 7.4 million before years ago, 2.9 to 3.1 million years ago. Karyological studies using staining of the chromosome bands by Romanenko et al (2007) put the other hand, suggests a closer relationship with the horror dwarf hamster and the hamster of. Neumann and co-workers (2006 ) represent the long-tailed dwarf hamster as a single species in the Cricetulus longicaudatus group and Pawlinow (2003) combines it with the Daurian dwarf hamster and the Sokolow - dwarf hamster in the subgenus Cricetulus.
Konstantin Alexeyevich Satunin united him against it in 1903 with the Kham- dwarf hamsters and the like, langschwänzigeren hamsters in the genus Urocricetus. John Reeves Ellerman took him in 1941 on the basis of literature also with the Kham- dwarf hamster in the Cricetulus longicaudatus group together. Ellerman and Morrison -Scott Terence Charles Stuart united him against it in 1951 with the horror dwarf hamsters and dwarf hamster in the Daurian Cricetulus migratorius group. Based on the literature associated Vladimir Jewgenjewitsch Flint him in 1966 again the Kham- dwarf hamster.
Inside systematics
Smith and Hoffmann ( 2008), Clark and colleagues ( 2006) and Gromov and Jerbajewa (1995 ) distinguish the following three sub-species of the long-tailed dwarf hamster:
- Cricetulus longicaudatus chiumalaiensis Wang & Cheng, 1973 in Qinghai and Tibet,
- Cricetulus longicaudatus longicaudatus ( Milne -Edwards 1867) in China and Mongolia with the synonyms andersoni Thomas, in 1908 in Shanxi, nigrescens Allen, 1925 in Hebei, dichrootis Satunin, 1903 at Nan Shan and griseiventris Satunin, 1903 in Mongolia and
- Cricetulus longicaudatus kozhantschikovi Vinogradov, 1927 in Tuva and in the Sayan Mountains.
Gromov and Jerbajewa (1995 ) acknowledge on the territory of the former Soviet Union Cricetulus longicaudatus kozhantschikovi ( in Tuva and in the Sayan Mountains ) as a subspecies, Clark and colleagues ( 2006) in Mongolia the subspecies Cricetulus longicaudatus longicaudatus. Smith and Hoffmann ( 2008) differ, however, in China, the two subspecies Cricetulus longicaudatus chiumalaiensis (southern Qinghai and Tibet ) and Cricetulus longicaudatus longicaudatus (in the north of Xinjiang, Inner Mongolia, Hebei, Beijing, Tianjin, in northern Henan in Shanxi, Shaanxi, Ningxia, Gansu and Qinghai ). Make nigrescens longicaudatus in the synonymy of Cricetulus longicaudatus.
John Reeves Ellerman, 1941, the different subspecies Cricetulus longicaudatus longicaudatus, Cricetulus longicaudatus griseiventris, Cricetulus longicaudatus dichrootis, Cricetulus longicaudatus andersoni, Cricetulus longicaudatus longicaudatus nigrescens and Cricetulus kozhantscikovi. Glover Morrill Allen arranged dichrootis contrast, in 1940 the Gobi dwarf hamsters, asked andersoni, does it in the synonymy of Cricetulus longicaudatus longicaudatus. Ellerman and Terence Charles Stuart Morrison -Scott united andersoni 1951 also with Cricetulus longicaudatus longicaudatus and distinguished the subspecies Cricetulus longicaudatus longicaudatus ( in Gansu, Shaanxi, Shanxi, Mongolia and Manchuria ), Cricetulus longicaudatus griseiventris, Cricetulus longicaudatus dichrootis, Cricetulus longicaudatus longicaudatus nigrescens and Cricetulus kozhantscikovi. Andrei Grigoryevich Bannikow summed up 1960, nigrescens with Cricetulus longicaudatus dichrootis together while Wang Sung and Cheng Chang -lin in 1973 both nigrescens and dichrootis presented in the synonymy of Cricetulus longicaudatus longicaudatus longicaudatus and Cricetulus chiumalaiensis led as a new subspecies. Gordon Barclay Corbet united 1978 dichrootis ( Nan Shan), griseiventris ( in Mongolia ), kozhantscikovi ( in the Sayan Mountains ) and nigrescens ( in Hebei ) also with Cricetulus longicaudatus longicaudatus and put this subspecies only Cricetulus longicaudatus chiumalaiensis opposite.
Nomenclature
The type specimen of the long-tailed dwarf hamster comes as that of the Gobi dwarf hamster probably from near " Saratsi " on the Yellow River about 60 kilometers west of Hohhot in Inner Mongolia today. It was collected by Armand David in 1867 by Alphonse Milne -Edwards in Recherches pour servir à l' histoire naturelle of mammifères as Cricetus ( Cricetulus ) longicaudatus ( from Latin longus, long ' and caudate, truant ') described and is probably in the Muséum national d' histoire naturelle in Paris. Konstantin Alexeyevich Satunin described in 1903 in New Rodents from Central Asia another copy of the " bis- shen- gol " on the south side of the Gobi - Altai as Cricetulus phaeus griseiventris (from the Latin griseis, gray ' and venter, belly ') and a copy of the " Gorban - angyr -gol " in Nan Shan as Cricetulus dichrootis ( from Ancient Greek δίχρως díchrōs, two-tone ' and ὠτός Otos genitive, ear '). An approximately 160 kilometers northwest of Taiyuan in Shanxi by M. P. Anderson collected specimen described Oldfield Thomas in 1908 List of Mammals from the Provinces of Chih -li and Shan -si, N. China andersoni as Cricetulus.
Glover Morrill Allen, described in 1925 a specimen about 160 kilometers northeast of Beijing andersoni as Cricetulus in Hebei nigrescens ( nigresco of latin, black be '). Bellows and skull of this on the led by Roy Chapman Andrews expedition collected in March 1922, the adult male are in the American Museum of Natural History in New York and bear the inventory number 56307th A copy of the " Tuksel -Chem " in the Sayan Mountains in Rajon Minusinsk described Boris Stepanovich Vinogradov 1927 as Cricetulus kozhantschikovi ( by Igor Vasilyevich Koschantschikow ). It is located in the Zoological Institute of the Russian Academy of Sciences in St. Petersburg. Wang Sung and Cheng Chang -lin finally described in 1973 a copy of the " Sewukou " Valley in the " Chiumalai " district in Qinghai as Cricetulus longicaudatus chiumalaiensis. The holotype with the inventory number 630 452 was collected on 31 August 1963 a paratype with the inventory number 630 477 on 1 September 1963, further copies from May to September 1960. All types are found in the Biological Institute of Qinghai Province, Xining.
Inventory and protection
The World Conservation Union IUCN classified the long-tailed dwarf hamster in 2008 as in 1996 as a not threatened (Least Concern ). This is justified by the large stocks and the ubiquity. A population decline could not be found and there are no known threats larger area. Regionally, it is true, according to IUCN in China ( 2004) and in Mongolia (2006) also considered not at risk.
Threats to the long-tailed dwarf hamster are not currently considered to be significant. A habitat loss could be caused by an increasing number of grazing cattle. In some areas, other rodents in the competition could occur for resources. He is also partially frustrated by the drying up of sources and droughts. It is unclear, however, whether these are natural or human-induced changes. In Mongolia, there are about 11 percent of its distribution area in protected areas.