The Ciscaucasian Hamster, (Mesocricetus raddei) is a species of rodent

Rodent

Rodentia is an order of mammals also known as rodents, characterised by two continuously growing incisors in the upper and lower jaws which must be kept short by gnawing....

 in the family Cricetidae

Cricetidae

The Cricetidae are a family of rodents in the large and complex superfamily Muroidea. It includes true hamsters, voles, lemmings, and New World rats and mice...

. It is also known as the Georgian hamster and is found only in Russia

Russia

Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

.

Distribution and habitat

This hamster occurs on the northern slopes of the Caucasus

Caucasus

The Caucasus, also Caucas or Caucasia , is a geopolitical region at the border of Europe and Asia, and situated between the Black and the Caspian sea...

 and Ciscaucasia

Ciscaucasia

Ciscaucasia , also Ciscaucasus or Fore-Caucasus, is a part of the Caucasus region, and of the North Caucasus in particular.The region is at the northern foothills of the Greater Caucasus range, from the Sea of Azov in the west to the Caspian Sea in the east, separated from the East European Plain...

, between Dagestan, the Don River

Don River (Russia)

The Don River is one of the major rivers of Russia. It rises in the town of Novomoskovsk 60 kilometres southeast from Tula, southeast of Moscow, and flows for a distance of about 1,950 kilometres to the Sea of Azov....

 and the Sea of Azov

Sea of Azov

The Sea of Azov , known in Classical Antiquity as Lake Maeotis, is a sea on the south of Eastern Europe. It is linked by the narrow Strait of Kerch to the Black Sea to the south and is bounded on the north by Ukraine mainland, on the east by Russia, and on the west by the Ukraine's Crimean...

. It is also known from a single record in Georgia

Georgia (country)

Georgia is a sovereign state in the Caucasus region of Eurasia. Located at the crossroads of Western Asia and Eastern Europe, it is bounded to the west by the Black Sea, to the north by Russia, to the southwest by Turkey, to the south by Armenia, and to the southeast by Azerbaijan. The capital of...

. It appears to be extending its range north and north-westwards in its plain

Plain

In geography, a plain is land with relatively low relief, that is flat or gently rolling. Prairies and steppes are types of plains, and the archetype for a plain is often thought of as a grassland, but plains in their natural state may also be covered in shrublands, woodland and forest, or...

s habitat

Habitat

* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...

s but in the mountains the population remains stable. It is found in grassy steppe

Steppe

In physical geography, steppe is an ecoregion, in the montane grasslands and shrublands and temperate grasslands, savannas, and shrublands biomes, characterized by grassland plains without trees apart from those near rivers and lakes...

s and also mountain steppes

Montane grasslands and shrublands

Montane grasslands and shrublands is a biome defined by the World Wildlife Fund. The biome includes high altitude grasslands and shrublands around the world....

 at elevations from 1600 to 2300 metres above sea level. It favours pasture and cultivated land and also occurs in belts of trees and rough grass between fields but not in dense woodland.

Morphology and biology

Hamsters of the subspecies found in mountainous regions are larger than the ones found on the plains. They are about 28 centimetres long with a short tail, 1.5 centimetres long. They are yellowish-brown above with creamy-white throat and underparts and a black ventral region. There are two broad black stripes at the shoulder and the ears are large and rounded. This hamster is considered an agricultural pest. It is mainly nocturnal, emerging at dusk to feed on grasses and herbs in spring and early summer, and on seeds, crops and roots in the autumn. The burrow

Burrow

A burrow is a hole or tunnel dug into the ground by an animal to create a space suitable for habitation, temporary refuge, or as a byproduct of locomotion. Burrows provide a form of shelter against predation and exposure to the elements, so the burrowing way of life is quite popular among the...

 is extensive and has several exits in the mountain subspecies but only one on the plains. Large stores of food (up to 16 kilogrammes) are laid up in the autumn before hibernation

Hibernation

Hibernation is a state of inactivity and metabolic depression in animals, characterized by lower body temperature, slower breathing, and lower metabolic rate. Hibernating animals conserve food, especially during winter when food supplies are limited, tapping energy reserves, body fat, at a slow rate...

 which lasts for four to six months depending on the temperature and altitude. This food is mostly eaten in the spring upon emergence from hibernation. In the mountains there are two generations each year but on the plains there may be three or four. Litter size is up to twenty and averages about twelve. This fecundity

Fecundity

Fecundity, derived from the word fecund, generally refers to the ability to reproduce. In demography, fecundity is the potential reproductive capacity of an individual or population. In biology, the definition is more equivalent to fertility, or the actual reproductive rate of an organism or...

means that the species can recover quickly after harsh winters and the population size is subject to considerable fluctuations.

Economic significance

In some years M. raddei becomes a considerable pest of agricultural crops. It can damage cereals and perennial grasses, disrupt potato plantings, melon fields and vegetable gardens. Close to the burrow the vegetation may be completely destroyed. It is sometimes trapped for its fur.