Cricetines first show up in the fossil record in the middle Miocene of Europe. The earliest fossils of living genera are Cricetus specimens from the late Miocene.
Hamsters perceive visual, tactile, auditory, and chemical stimuli. They seem to rely most on vision when searching for live prey, but hearing and olfaction are also important (Langley 1985).
Hamsters use chemical cues to communicate. Males scent-mark their territories with their large sebaceous flank glands. In fact, the size of these glands is correlated with an individual's status in the dominance hierarchy: the larger the glands, the more dominant the animal.
Communication Channels: chemical
Other Communication Modes: scent marks
Perception Channels: visual ; tactile ; acoustic ; chemical
The IUCN currently lists one species in this subfamily as endangered (the popular pet, golden or Syrian hamsters, Mesocricetus auratus), one as vulnerable (Romanian hamsters, Mesocricetus newtoni), and one as lower risk (gray dwarf hamsters, Cricetulus migratorius). Although hamsters breed readily and are abundant in captivity, wild populations of some species have restricted ranges and are vulnerable to habitat destruction.
Cricetines, or hamsters, make up a small Old World subfamily of terrestrial cricetid rodents. There are 18 hamster species in 7 genera.
Some hamster species feed on beans, corn, and lentils, and are thus considered crop pests.
Negative Impacts: crop pest
Some hamster species thrive in captivity and make good pets, and they are also used in laboratories for behavioral and physiological research. Others are trapped for their skins.
Positive Impacts: pet trade ; research and education
As herbivores and carnivores, cricetines are primary, secondary, and in some cases, tertiary consumers. They are, in turn, food for various higher-level consumers. Their habit of storing seeds may mean that they play a role in seed dispersal.
Ecosystem Impact: disperses seeds
Cricetines are primarily granivorous, but they also consume leaves, shoots, roots, and fruit. In addition, some species are omnivorous and eat insects and even vertebrates such as frogs. They cram food into their large cheek pouches and take it back to store in their burrows. Hamster burrows have been found with as much as 90 kg of stored food.
Foraging Behavior: stores or caches food
Primary Diet: carnivore (Eats terrestrial vertebrates, Insectivore ); herbivore (Folivore , Frugivore , Granivore ); omnivore
Cricetine rodents have a Palearctic distribution. They are found in central and eastern Europe, in Asia Minor, Syria, and Iran, in Mongolia, Siberia, northern China, and Korea.
Biogeographic Regions: palearctic (Native )
Cricetines are most common in dry, open habitats. They live in deserts, plains, sand dunes, steppes, shrublands, rocky foothills, river valleys, agricultural fields, gardens, and orchards. Hamsters may be found at elevations up to 3,600 meters.
Habitat Regions: temperate ; terrestrial
Terrestrial Biomes: desert or dune ; savanna or grassland ; chaparral ; scrub forest
Other Habitat Features: agricultural ; riparian
The record longevity for a wild hamster is ten years. This is an unusual case, however, and most wild and captive hamsters live two to four years. Common causes of mortality in the wild are predation, harsh winters, disease, and, in agricultural areas, crushing by heavy machinery.
Hamsters are small to large muroid rodents with compact bodies, small, furry ears, short legs, wide feet, and short stubby tails. Body lengths range from 50 mm to 340 mm, and tail lengths range from 7 to 106 mm. Females of some species are larger than males. Hamsters have long, thick fur. They are gray, pinkish buff, light brown, or reddish brown on the dorsal surface and white, gray, or black on the ventral surface. Their flanks are often white as well. Some have a middorsal stripe. Hamsters have large cheek pouches and sebaceous flank glands.
The dental formula of hamsters is 1/1, 0/0, 0/0, 3/3 = 16. The incisors are orthodont and ungrooved, and the molars are rooted and cuspidate. The upper molars have deep labial re-entrant angles, and most cricetines have molars with opposite cusps. The dentary has a pronounced sigmoid notch and coronoid process. The rostrum is long, wide, and robust. The area between the orbits is hourglass shaped, and the zygomatic plate usually lacks a spine or notch. The incisive foramena are usually short. The sphenopalatine vacuities are moderately large. There is a postglenoid foramen, and most have a sphenofrontal foramen and squamosoalisphenoid groove. The bony palate is wide and smooth, and there is usually a single pair of posterior palatine foramina. A strut of the alisphenoid bone separates the masticatory foramen and accessory foramen ovale. Cricentines have vertebral columns with 13 thoracic vertebrae and six lumbar vertebrae.
Hamsters have two-chambered stomachs, and most lack a gall bladder. Their large intestines and ceca are moderately complex. Hamsters have a diploid chromosome number between 20 and 44.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: sexes alike; female larger
Animals that prey on hamsters include diurnal raptors, snakes, and mammalian carnivores. Species that are known to eat hamsters are red kites, black kites, common buzzards, lesser spotted eagles, red foxes, domestic dogs, ermine, and Eurasian badgers. Predators such as common kestrels, grey herons, carrion crows, and rooks prey on juvenile hamsters.
Hamsters can be aggressive and do not hesitate to defend themselves from predators with their large incisors. Females sometimes protect their young from predators by carrying them in their cheek pouches. Finally, like the fur of most rodents, hamster fur comes in neutral colors, affording these animals some degree of camouflage.
Known Predators:
Anti-predator Adaptations: cryptic
Cricetines are promiscuous, with males and females both having multiple mates. During the breeding season, male hamsters have been seen wandering down any burrows they find, looking for female hamsters. During mating, a copulatory plug forms and seals the female's reproductive tract, preventing subsequent males from successfully fertilizing the female's eggs. A female hamster often drives a male out of her territory soon after mating.
Mating System: polygynandrous (promiscuous)
Cricetines are seasonal breeders that mate and raise their litters from February to November. Females bear between two and four litters per year. Gestation is short, lasting 15 to 22 days, and litter sizes average 5 to 7 but can be as small as one and as large as 13. Young hamsters nurse for about three weeks, and are sexually mature at six to eight weeks.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous
Female hamsters nurse their altricial offspring for about three weeks. Some species are known to stuff their youngsters into their cheek pouches when danger threatens and move elsewhere.
Parental Investment: altricial ; pre-fertilization (Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female)
