Hamsters are
rodent
Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are na ...
s (order Rodentia) belonging to the
subfamily
In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoologi ...
Cricetinae, which contains 19
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
classified in seven
genera
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...
.
[Fox, Sue. 2006. ''Hamsters''. T.F.H. Publications Inc.] They have become established as popular
small pet
The most common rodents kept as household pets are hamsters (golden hamsters and dwarf hamsters), gerbils (Mongolian jirds and duprasi gerbils), common degus, fancy mice, fancy rats, common chinchillas, and guinea pigs (cavies).
The domesti ...
s.
[ The best-known species of hamster is the golden or Syrian hamster (''Mesocricetus auratus''), which is the type most commonly kept as pets. Other hamster species commonly kept as pets are the three species of dwarf hamster, ]Campbell's dwarf hamster
Campbell's dwarf hamster (''Phodopus campbelli'') is a species of hamster in the genus ''Phodopus''. It was given its common name by Oldfield Thomas in honor of Charles William Campbell, who collected the first specimen in Mongolia on July 1, 1 ...
(''Phodopus campbelli''), the winter white dwarf hamster
The winter white dwarf hamster (''Phodopus sungorus''), also known as the Russian dwarf hamster, Djungarian hamster, striped dwarf hamster, Siberian hamster, or Siberian dwarf hamster, is one of three species of hamster in the genus '' Phodopus' ...
(''Phodopus sungorus'') and the Roborovski hamster
The Roborovski hamster (''Phodopus roborovskii''), also known as the desert hamster, Robo dwarf hamster, or simply dwarf hamster, is the smallest of three species of hamster in the genus ''Phodopus''. It lives in the deserts of Central Asia, avera ...
(''Phodopus roborovskii'').
Hamsters are more crepuscular
In zoology, a crepuscular animal is one that is active primarily during the twilight period, being matutinal, vespertine, or both. This is distinguished from diurnal and nocturnal behavior, where an animal is active during the hours of daylig ...
than nocturnal
Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite.
Nocturnal creatures generally have highly developed sens ...
and, in the wild, remain underground during the day to avoid being caught by predators. They feed primarily on seeds, fruits, and vegetation, and will occasionally eat burrowing insects. Physically, they are stout-bodied with distinguishing features that include elongated cheek pouch
Cheek pouches are pockets on both sides of the head of some mammals between the jaw and the cheek. They can be found on mammals including the platypus, some rodents, and most monkeys, as well as the marsupial koala. The cheek pouches of chipmunks ...
es extending to their shoulders, which they use to carry food back to their burrows, as well as a short tail and fur-covered feet.
Classification
Taxonomists generally disagree about the most appropriate placement of the subfamily Cricetinae within the superfamily Muroidea
The Muroidea are a large superfamily of rodents, including mice, rats, voles, hamsters, lemmings, gerbils, and many other relatives. Although the Muroidea originated in Eurasia, they occupy a vast variety of habitats on every continent excep ...
. Some place it in a family Cricetidae
The Cricetidae are a family of rodents in the large and complex superfamily Muroidea. It includes true hamsters, voles, lemmings, muskrats, and New World rats and mice. At almost 608 species, it is the second-largest family of mammals, and has m ...
that also includes vole
Voles are small rodents that are relatives of lemmings and hamsters, but with a stouter body; a longer, hairy tail; a slightly rounder head; smaller eyes and ears; and differently formed molars (high-crowned with angular cusps instead of low-c ...
s, lemming
A lemming is a small rodent, usually found in or near the Arctic in tundra biomes. Lemmings form the subfamily Arvicolinae (also known as Microtinae) together with voles and muskrats, which form part of the superfamily Muroidea, which also includ ...
s, and New World rats and mice
The New World rats and mice are a group of related rodents found in North and South America. They are extremely diverse in appearance and ecology, ranging in from the tiny ''Baiomys'' to the large ''Kunsia''. They represent one of the few exampl ...
; others group all these into a large family called Muridae
The Muridae, or murids, are the largest family of rodents and of mammals, containing approximately 1,383 species, including many species of mice, rats, and gerbils found naturally throughout Eurasia, Africa, and Australia.
The name Muridae come ...
. Their evolutionary history is recorded by 15 extinct fossil genera and extends back 11.2 million to 16.4 million years to the Middle Miocene
The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...
Epoch in Europe and North Africa; in Asia it extends 6 million to 11 million years. Four of the seven living genera include extinct species. One extinct hamster of ''Cricetus
The European hamster (''Cricetus cricetus''), also known as the Eurasian hamster, black-bellied hamster or common hamster, is the only species of hamster in the genus ''Cricetus''. It is native to grassland and similar habitats in a large part ...
'', for example, lived in North Africa during the Middle Miocene, but the only extant member of that genus is the European or common hamster of Eurasia.
*Subfamily Cricetinae
**Genus ''Allocricetulus
''Allocricetulus'' is a genus of hamsters in the family Cricetidae, which are found in Asia. It contains the following species:
* Mongolian hamster
The Mongolian hamster (''Allocricetulus curtatus'') is a species of rodent in the family Cricet ...
''
***Species ''A. curtatus''—Mongolian hamster
***Species ''A. eversmanni''—Eversmann's or Kazakh hamster
**Genus '' Cansumys''
***Species ''C. canus''—Gansu hamster
**Genus '' Cricetulus''
***Species ''C. alticola''—Tibetan dwarf or Ladak hamster
***Species ''C. barabensis'', including "''C. pseudogriseus''" and "''C. obscurus''"—Chinese striped hamster, also called Chinese hamster; striped dwarf hamster
***Species ''C. griseus''—Chinese (dwarf) hamster, also called rat hamster
***Species ''C. kamensis''—Kam dwarf hamster or Tibetan hamster
***Species ''C. longicaudatus''—long-tailed dwarf hamster
***Species ''C. migratorius''—grey dwarf hamster, Armenian hamster, migratory grey hamster; grey hamster; migratory hamster
***Species ''C. sokolovi''—Sokolov's dwarf hamster
**Genus ''Cricetus
The European hamster (''Cricetus cricetus''), also known as the Eurasian hamster, black-bellied hamster or common hamster, is the only species of hamster in the genus ''Cricetus''. It is native to grassland and similar habitats in a large part ...
''
***Species ''C. cricetus''—European hamster, also called common hamster or black-bellied field hamster
**Genus ''Mesocricetus
''Mesocricetus'' is a genus of Old World hamsters, including the Syrian or golden hamster, the first hamster to be introduced as a domestic pet, and still the most popular species of hamster for that purpose.
Recent research has shown that, unl ...
''—golden hamsters
***Species ''M. auratus''—golden or Syrian hamster
***Species ''M. brandti''—Turkish hamster, also called Brandt's hamster; Azerbaijani hamster
***Species ''M. newtoni''—Romanian hamster
***Species ''M. raddei''—Ciscaucasian hamster
**Genus ''Phodopus
''Phodopus'', a genus of rodents in the hamster subfamily Cricetinae—a division of the larger family Cricetidae—is a lineage of small hamsters native to central Asia that display unusual adaptations to extreme temperatures. They are the onl ...
''—dwarf hamsters
***Species ''P. campbelli''—Campbell's dwarf hamster
***Species ''P. roborovskii''—Roborovski hamster
***Species ''P. sungorus''—Djungarian hamster or winter-white Russian dwarf hamster
**Genus ''Tscherskia
The greater long-tailed hamster (''Tscherskia triton'') is a rodent native to Siberia, the Korean Peninsula, and China. It is the only member of the genus ''Tscherskia''. Taxonomy
The genetic diversity of ''Tscherskia triton'' has a positive c ...
''
***Species ''T. triton''—greater long-tailed hamster, also called Korean hamster
Relationships among hamster species
Neumann ''et al.'' (2006) conducted a molecular phylogenetic
Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...
analysis of 12 of the above 17 species using DNA sequence
DNA sequencing is the process of determining the nucleic acid sequence – the order of nucleotides in DNA. It includes any method or technology that is used to determine the order of the four bases: adenine, guanine, cytosine, and thymine. Th ...
from three gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...
s: 12S rRNA, cytochrome b
Cytochrome b within both molecular and cell biology, is a protein found in the mitochondria of eukaryotic cells. It functions as part of the electron transport chain and is the main subunit of transmembrane cytochrome bc1 and b6f complexes.
F ...
, and von Willebrand factor
Von Willebrand factor (VWF) () is a blood glycoprotein involved in hemostasis, specifically, platelet adhesion. It is deficient and/or defective in von Willebrand disease and is involved in many other diseases, including thrombotic thrombocytopen ...
. They uncovered the following relationships:[
;''Phodopus'' group
The genus ''Phodopus'' was found to represent the earliest split among hamsters. Their analysis included both species. The results of another study][ suggest ''Cricetulus kamensis'' (and presumably the related ''C. alticola'') might belong to either this ''Phodopus'' group or hold a similar basal position.
;''Mesocricetus'' group
The genus ''Mesocricetus'' also forms a ]clade
A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...
. Their analysis included all four species, with ''M. auratus'' and ''M. raddei'' forming one subclade and ''M. brandti'' and ''M. newtoni'' another.
;Remaining genera
The remaining genera of hamsters formed a third major clade. Two of the three sampled species within ''Cricetulus'' represent the earliest split. This clade contains ''C. barabensis'' (and presumably the related ''C. sokolovi'') and ''C. longicaudatus''.
;Miscellaneous
The remaining clade contains members of ''Allocricetulus'', ''Tscherskia'', ''Cricetus'', and ''C. migratorius''. ''Allocricetulus'' and ''Cricetus'' were sister taxa
In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree.
Definition
The expression is most easily illustrated by a cladogram:
Taxon A and ...
. ''Cricetulus migratorius'' was their next closest relative, and ''Tscherskia'' was basal.
History
Although the Syrian hamster or golden hamster
The golden hamster or Syrian hamster (''Mesocricetus auratus'') is a rodent belonging to the hamster subfamily, Cricetinae. Their natural geographical range is in an arid region of northern Syria and southern Turkey. Their numbers have been de ...
(''Mesocricetus auratus'') was first described scientifically by George Robert Waterhouse
George Robert Waterhouse (6 March 1810 – 21 January 1888) was an English natural history, naturalist. He was a keeper at the department of geology and later curator of the Zoological Society of London's museum.
Early life
George was born ...
in 1839, researchers were not able to successfully breed and domesticate hamsters until 1939.[Barrie, Anmarie. 1995. Hamsters as a New Pet. T.F.H. Publications Inc., NJ .] The entire laboratory and pet populations of Syrian hamsters appear to be descendants of a single brother–sister pairing. These littermates were captured and imported in 1930 from Aleppo in Syria by Israel Aharoni
Israel Aharoni (1882 - 1946 he, ישראל אהרוני) was a zoologist in Ottoman and British Palestine widely known as the "first Hebrew zoologist."
Aharoni is best known for collecting a litter of Syrian hamsters on an expedition to Ale ...
, a zoologist of the University of Jerusalem
The Hebrew University of Jerusalem (HUJI; he, הַאוּנִיבֶרְסִיטָה הַעִבְרִית בִּירוּשָׁלַיִם) is a public research university based in Jerusalem, Israel. Co-founded by Albert Einstein and Dr. Chaim Weiz ...
.[Fritzsche, Peter. 2008. Hamsters: A Complete Pet Owner's Manual. Barron's Educational Series Inc., NY .] In Jerusalem, the hamsters bred very successfully. Years later, animals of this original breeding colony were exported to the United States, where Syrian hamsters became a common pet and laboratory animal. Comparative studies of domestic and wild Syrian hamsters have shown reduced genetic variability in the domestic strain. However, the differences in behavioral, chronobiological, morphometrical, hematological, and biochemical parameters are relatively small and fall into the expected range of interstrain variations in other laboratory animals.[Kuhnen, G. (2002). Comfortable quarters for hamsters in research institutions. In "Comfortable Quarters for Laboratory Animals" Eds V. Reinhardt and A. Reinhardt. Animal Welfare Institute, Washington DC. pp.33-37]
Etymology
The name "hamster" is a loanword
A loanword (also loan word or loan-word) is a word at least partly assimilated from one language (the donor language) into another language. This is in contrast to cognates, which are words in two or more languages that are similar because th ...
from the German, which itself derives from earlier Middle High German
Middle High German (MHG; german: Mittelhochdeutsch (Mhd.)) is the term for the form of German spoken in the High Middle Ages. It is conventionally dated between 1050 and 1350, developing from Old High German and into Early New High German. High ...
''hamastra''. It is possibly related to Old Church Slavonic
Old Church Slavonic or Old Slavonic () was the first Slavic languages, Slavic literary language.
Historians credit the 9th-century Byzantine Empire, Byzantine missionaries Saints Cyril and Methodius with Standard language, standardizing the lan ...
''khomestoru'', which is either a blend of the root of Russian
Russian(s) refers to anything related to Russia, including:
*Russians (, ''russkiye''), an ethnic group of the East Slavic peoples, primarily living in Russia and neighboring countries
*Rossiyane (), Russian language term for all citizens and peo ...
хомяк (''khomyak'') "hamster" and a Baltic word (cf. Lithuanian ''staras'' "hamster"); or of Persian origin (cf. Av ''hamaēstar'' "oppressor"). The collective noun for a group of hamsters is "horde". In German, the verb "hamstern" is derived from "Hamster". It means "Hoarding
Hoarding is a behavior where people or animals accumulate food or other items.
Animal behavior
''Hoarding'' and ''caching'' are common in many bird species as well as in rodents. Most animal caches are of food. However, some birds will a ...
".
Description
Hamsters are typically stout-bodied, with tails shorter than body length, and have small, furry ears, short, stocky legs, and wide feet. They have thick, silky fur, which can be long or short, colored black, grey, honey, white, brown, yellow, red, or a mix, depending on the species. Two species of hamster belonging to the genus ''Phodopus
''Phodopus'', a genus of rodents in the hamster subfamily Cricetinae—a division of the larger family Cricetidae—is a lineage of small hamsters native to central Asia that display unusual adaptations to extreme temperatures. They are the onl ...
'', Campbell's dwarf hamster
Campbell's dwarf hamster (''Phodopus campbelli'') is a species of hamster in the genus ''Phodopus''. It was given its common name by Oldfield Thomas in honor of Charles William Campbell, who collected the first specimen in Mongolia on July 1, 1 ...
(''P. campbelli'') and the Djungarian hamster
The winter white dwarf hamster (''Phodopus sungorus''), also known as the Russian dwarf hamster, Djungarian hamster, striped dwarf hamster, Siberian hamster, or Siberian dwarf hamster, is one of three species of hamster in the genus ''Phodopus'' ...
(''P. sungorus''), and two of the genus '' Cricetulus'', the Chinese striped hamster
The Chinese striped hamster (''Cricetulus barabensis''), also known as the striped dwarf hamster, is a species of hamster. It is distributed across Northern Asia, from southern Siberia through Mongolia and northeastern China to northern North Ko ...
(''C. barabensis'') and the Chinese hamster (''C. griseus'') have a dark stripe down their heads to their tails. The species of genus ''Phodopus'' are the smallest, with bodies long; the largest is the European hamster
The European hamster (''Cricetus cricetus''), also known as the Eurasian hamster, black-bellied hamster or common hamster, is the only species of hamster in the genus ''Cricetus''. It is native to grassland and similar habitats in a large part ...
(''Cricetus cricetus''), measuring up to long, not including a short tail of up to .
The hamster tail can be difficult to see, as it is usually not very long (about the length of the body), with the exception of the Chinese hamster, which has a tail the same length as the body. One rodent characteristic that can be highly visible in hamsters is their sharp incisors
Incisors (from Latin ''incidere'', "to cut") are the front teeth present in most mammals. They are located in the premaxilla above and on the mandible below. Humans have a total of eight (two on each side, top and bottom). Opossums have 18, wh ...
; they have an upper pair and lower pair which grow continuously throughout life, so must be regularly worn down. Hamsters are very flexible, however their bones are somewhat fragile. They are extremely susceptible to rapid temperature changes and drafts, as well as extreme heat or cold.
Senses
Hamsters have poor eyesight; they are nearsighted
Near-sightedness, also known as myopia and short-sightedness, is an eye disease where light focuses in front of, instead of on, the retina. As a result, distant objects appear blurry while close objects appear normal. Other symptoms may include ...
and colorblind
Color blindness or color vision deficiency (CVD) is the decreased ability to see color or differences in color. It can impair tasks such as selecting ripe fruit, choosing clothing, and reading traffic lights. Color blindness may make some aca ...
. Their eyesight leads to them not having a good sense of distance or knowing where they are. Even though their eyesight isn't good it doesn't stop a hamster from climbing their cages or even from them being adventurous. Hamsters can sense movement around at all times. This sense helps them protect themselves from harm in the wild but in a household situation it helps them sense when their owner may be near and might be going to pick them up. Hamsters have scent glands
Scent gland are exocrine glands found in most mammals. They produce semi-viscous secretions which contain pheromones and other semiochemical compounds. These odor-messengers indicate information such as status, territorial marking, mood, and sexu ...
on their flanks (and abdomens in Chinese and dwarf hamsters) which they rub against the substrate, leaving a scent trail. Hamsters also use their sense of smell to distinguish between the sexes, and to locate food. Mother hamsters can also use their sense of smell to find their own babies and find out which ones aren't theirs. The scent glands can also be used to mark their territories, their babies, or their mate. Hamsters catch sounds by having their ears upright. They tend to learn similar noises and begin to know the sound of their food and even their owner's voice. They are also particularly sensitive to high-pitched noises and can hear and communicate in the ultrasonic
Ultrasound is sound waves with frequencies higher than the upper audible limit of human hearing. Ultrasound is not different from "normal" (audible) sound in its physical properties, except that humans cannot hear it. This limit varies fr ...
range.
Diet
Hamsters are omnivores
An omnivore () is an animal that has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize the nutri ...
, which means they can eat meat and vegetables. Hamsters that live in the wild eat seeds, grass, and even insects. Although pet hamsters can survive on a diet of exclusively commercial hamster food, other items, such as vegetables, fruits, seeds, and nuts, can be given. Although store-bought food is good for hamsters, it is best if fruits and vegetables are also in their diet because it keeps them healthier. Even though hamsters are allowed to have both fruits and vegetables, it is important to understand exactly which ones they can have and how much. Hamsters do best with fruits that don't have citrus in them and most green leafy vegetables. Hamsters should never be fed junk food, chocolate, garlic, or any salty/sugary foods. Hamsters tend to love peanut butter but it is important to feed it to them carefully because this sticky food can get stuck in their cheeks. Hamsters in the Middle East have been known to hunt in packs to find insects for food.["hamster." ]Encyclopædia Britannica
The (Latin for "British Encyclopædia") is a general knowledge English-language encyclopaedia. It is published by Encyclopædia Britannica, Inc.; the company has existed since the 18th century, although it has changed ownership various time ...
. Standard Edition. Chicago: Encyclopædia Britannica, 2007. Hamsters are hindgut fermenters
Hindgut fermentation is a digestive process seen in monogastric herbivores, animals with a simple, single-chambered stomach. Cellulose is digested with the aid of symbiotic bacteria.[coprophagy
Coprophagia () or coprophagy () is the consumption of feces. The word is derived from the grc, κόπρος , "feces" and , "to eat". Coprophagy refers to many kinds of feces-eating, including eating feces of other species (heterospecifics), o ...]
) to recover nutrients digested in the hind-gut, but not absorbed.
Behavior
Feeding
A behavioral characteristic of hamsters is food hoarding. They carry food in their spacious cheek pouches to their underground storage chambers. When full, the cheeks can make their heads double, or even triple in size. Hamsters lose weight during the autumn months in anticipation of winter. This occurs even when hamsters are kept as pets and is related to an increase in exercise.
Social behavior
Most hamsters are strictly solitary. If housed together, acute and chronic stress
Stress may refer to:
Science and medicine
* Stress (biology), an organism's response to a stressor such as an environmental condition
* Stress (linguistics), relative emphasis or prominence given to a syllable in a word, or to a word in a phrase ...
may occur, and they may fight fiercely, sometimes fatally. Dwarf hamster Dwarf hamster may refer to:
*A member of any of the three species of genus ''Phodopus'':
**Campbell's dwarf hamster
**Djungarian hamster
**Roborovski hamster
*A member of certain species of genus ''Cricetulus'':
**Tibetan dwarf hamster
**Chinese str ...
species may tolerate siblings
A sibling is a relative that shares at least one parent with the subject. A male sibling is a brother and a female sibling is a sister. A person with no siblings is an only child.
While some circumstances can cause siblings to be raised separat ...
or same-gender unrelated hamsters if introduced at an early enough age, but this cannot be guaranteed. Hamsters communicate through body language to one another and even to their owner. They communicate by sending a specific scent using their scent glands and also show body language to express how they are feeling.
Chronobiology
Hamsters can be described as nocturnal
Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite.
Nocturnal creatures generally have highly developed sens ...
or crepuscular
In zoology, a crepuscular animal is one that is active primarily during the twilight period, being matutinal, vespertine, or both. This is distinguished from diurnal and nocturnal behavior, where an animal is active during the hours of daylig ...
(active mostly at dawn and dusk). Khunen writes, "Hamsters are nocturnal rodents who are active during the night...", but others have written that because hamsters live underground during most of the day, only leaving their burrows for about an hour before sundown and then returning when it gets dark, their behavior is primarily crepuscular. Fritzsche indicated although some species have been observed to show more nocturnal activity than others, they are all primarily crepuscular.
In the wild Syrian hamsters can hibernate
Hibernation is a state of minimal activity and metabolic depression undergone by some animal species. Hibernation is a seasonal heterothermy characterized by low body-temperature, slow breathing and heart-rate, and low metabolic rate. It most ...
and allow their body temperature to fall close to ambient temperature. This kind of thermoregulation
Thermoregulation is the ability of an organism to keep its body temperature within certain boundaries, even when the surrounding temperature is very different. A thermoconforming organism, by contrast, simply adopts the surrounding temperature ...
diminishes the metabolic rate
Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run ce ...
to about 5% and helps the animal to considerably reduce the need for food during the winter. Hibernation can last up to one week but more commonly last 2–3 days. When kept as house pets the Syrian hamster does not hibernate.
Burrowing behavior
All hamsters are excellent diggers, constructing burrows with one or more entrances, with galleries connected to chambers for nesting, food storage, and other activities. They use their fore- and hindlegs, as well as their snouts and teeth, for digging. In the wild, the burrow buffers extreme ambient temperatures, offers relatively stable climatic conditions, and protects against predators. Syrian hamsters dig their burrows generally at a depth of 0.7 m. A burrow includes a steep entrance pipe (4–5 cm in diameter), a nesting and a hoarding chamber and a blind-ending branch for urination. Laboratory hamsters have not lost their ability to dig burrows; in fact, they will do this with great vigor and skill if they are provided with the appropriate substrate.
Wild hamsters will also appropriate tunnels made by other mammals; the Djungarian hamster, for instance, uses paths and burrows of the pika
A pika ( or ; archaically spelled pica) is a small, mountain-dwelling mammal found in Asia and North America. With short limbs, very round body, an even coat of fur, and no external tail, they resemble their close relative, the rabbit, but wi ...
.
Reproduction
Fertility
Hamsters become fertile
Fertility is the capability to produce offspring through reproduction following the onset of sexual maturity. The fertility rate is the average number of children born by a female during her lifetime and is quantified demographically. Fertilit ...
at different ages depending on their species. Both Syrian and Russian hamsters mature quickly and can begin reproducing at a young age (4–5 weeks), whereas Chinese hamsters will usually begin reproducing at two to three months of age, and Roborovskis at three to four months of age. The female's reproductive life lasts about 18 months, but male hamsters remain fertile much longer. Females are in estrus
The estrous cycle (, originally ) is the set of recurring physiological changes that are induced by reproductive hormones in most mammalian therian females. Estrous cycles start after sexual maturity in females and are interrupted by anestrous ...
about every four days, which is indicated by a reddening of genital areas, a musky smell, and a hissing, squeaking vocalisation she will emit if she believes a male is nearby.[
When seen from above, a ]sexually mature
Sexual maturity is the capability of an organism to reproduce. In humans it might be considered synonymous with adulthood, but here puberty is the name for the process of biological sexual maturation, while adulthood is based on cultural definiti ...
female hamster has a trim tail line; a male's tail line bulges on both sides. This might not be very visible in all species. Male hamsters typically have very large testes
A testicle or testis (plural testes) is the male reproductive gland or gonad in all bilaterians, including humans. It is homologous to the female ovary. The functions of the testes are to produce both sperm and androgens, primarily testoster ...
in relation to their body size. Before sexual maturity occurs, it is more difficult to determine a young hamster's sex. When examined, female hamsters have their anal and genital openings close together, whereas males have these two holes farther apart (the penis is usually withdrawn into the coat and thus appears as a hole or pink pimple).[
]
Gestation and fecundity
Syrian hamsters are seasonal breeder
Seasonal breeders are animal species that successfully mate only during certain times of the year. These times of year allow for the optimization of survival of young due to factors such as ambient temperature, food and water availability, and ch ...
s and will produce several litters a year with several pups in each litter. The breeding season is from April to October in the Northern Hemisphere, with two to five litters of one to 13 young being born after a gestation period of 16 to 23 days. Dwarf hamsters breed all through the year. Gestation lasts 16 to 18 days for Syrian hamsters, 18 to 21 days for Russian hamsters, 21 to 23 days for Chinese hamsters and 23 to 30 for Roborovski hamsters. The average litter size for Syrian hamsters is about seven pups, but can be as great as 24, which is the maximum number of pups that can be contained in the uterus. Campbell's dwarf hamster
Campbell's dwarf hamster (''Phodopus campbelli'') is a species of hamster in the genus ''Phodopus''. It was given its common name by Oldfield Thomas in honor of Charles William Campbell, who collected the first specimen in Mongolia on July 1, 1 ...
s tend to have four to eight pups in a litter, but can have up to 13. Winter white hamsters tend to have slightly smaller litters, as do Chinese and Roborovski hamsters.
Intersexual aggression and cannibalism
Female Chinese and Syrian hamsters are known for being aggressive toward males if kept together for too long after mating. In some cases, male hamsters can die after being attacked by a female. If breeding hamsters, separation of the pair after mating is recommended, or they will attack each other.
Female hamsters are also particularly sensitive to disturbances while giving birth, and may even eat their own young if they think they are in danger, although sometimes they are just carrying the pups in their cheek pouches. If captive female hamsters are left for extended periods (three weeks or more) with their litter, they may cannibalize the litter, so the litter must be removed by the time the young can feed and drink independently.
Weaning
Hamsters are born hairless and blind in a nest the mother will have prepared in advance.[ After one week, they begin to explore outside the nest. Hamsters are capable of producing litters every month. Hamsters can be bred after they are three weeks old. It may be hard for the babies to not rely on their mother for nursing during this time, so it is important that they are supplied with food to make the transition from nursing to eating on their own easier. After the hamsters reach three weeks of age they are considered mature.
]
Longevity
Syrian hamsters typically live no more than two to three years in captivity, and less in the wild. Russian hamsters (Campbell's and Djungarian) live about two to four years in captivity, and Chinese hamsters –3 years. The smaller Roborovski hamster often lives to three years in captivity.
Society and culture
Hamsters as pets
The best-known species of hamster is the golden or Syrian hamster (''Mesocricetus auratus''), which is the type most commonly kept as pet
A pet, or companion animal, is an animal kept primarily for a person's company or entertainment rather than as a working animal, livestock, or a laboratory animal. Popular pets are often considered to have attractive appearances, intelligence ...
s. There are numerous Syrian hamster variations including long-haired varieties and different colors. British zoologist Leonard Goodwin
Leonard George Goodwin CMG FRS (11 July 1915 – 25 November 2008) was a British protozoologist noted for his work on testing the effectiveness of chemical compounds in treating tropical diseases. He was born in London to a shoe shop manager, an ...
claimed most hamsters kept in the United Kingdom were descended from the colony he introduced for medical research purposes during the Second World War. Hamsters were domesticated and kept as pets in the United States at least as early as 1942.
Other hamsters commonly kept as pets are the three species of dwarf hamster Dwarf hamster may refer to:
*A member of any of the three species of genus ''Phodopus'':
**Campbell's dwarf hamster
**Djungarian hamster
**Roborovski hamster
*A member of certain species of genus ''Cricetulus'':
**Tibetan dwarf hamster
**Chinese str ...
. Campbell's dwarf hamster
Campbell's dwarf hamster (''Phodopus campbelli'') is a species of hamster in the genus ''Phodopus''. It was given its common name by Oldfield Thomas in honor of Charles William Campbell, who collected the first specimen in Mongolia on July 1, 1 ...
(''Phodopus campbelli'') is the most common—they are also sometimes called "Russian dwarfs"; however, many hamsters are from Russia, so this ambiguous name does not distinguish them from other species appropriately. The coat of the winter white dwarf hamster
The winter white dwarf hamster (''Phodopus sungorus''), also known as the Russian dwarf hamster, Djungarian hamster, striped dwarf hamster, Siberian hamster, or Siberian dwarf hamster, is one of three species of hamster in the genus '' Phodopus' ...
(''Phodopus sungorus'') turns almost white during winter (when the hours of daylight decrease).[ The ]Roborovski hamster
The Roborovski hamster (''Phodopus roborovskii''), also known as the desert hamster, Robo dwarf hamster, or simply dwarf hamster, is the smallest of three species of hamster in the genus ''Phodopus''. It lives in the deserts of Central Asia, avera ...
(''Phodopus roborovskii'') is extremely small and fast, making it difficult to keep as a pet.
Hamster shows
A hamster show is an event in which people gather hamsters to judge them against each other. Hamster shows are also places where people share their enthusiasm for hamsters among attendees. Hamster shows feature an exhibition of the hamsters participating in the judging.
The judging of hamsters usually includes a goal of promoting hamsters which conform to natural or established varieties of hamsters. By awarding hamsters which match standard hamster types, hamster shows encourage planned and careful hamster breeding.
Owner activism
When the first reported case of animal-to-human transmission of SARS-CoV-2
Severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) is a strain of coronavirus that causes COVID-19 (coronavirus disease 2019), the respiratory illness responsible for the ongoing COVID-19 pandemic. The virus previously had a ...
in Hong Kong
Hong Kong ( (US) or (UK); , ), officially the Hong Kong Special Administrative Region of the People's Republic of China ( abbr. Hong Kong SAR or HKSAR), is a city and special administrative region of China on the eastern Pearl River Delt ...
took place via imported pet hamsters, researchers expressed difficulty in identifying some of the viral mutations within a global genomic data bank, leading city authorities to announce a mass cull of all hamsters purchased after December 22, 2021, which would affect roughly 2,000 animals. After the government 'strongly encouraged' citizens to turn in their pets, approximately 3,000 people joined underground activities to promote the adoption of abandoned hamsters throughout the city and to maintain pet ownership via methods such as the forgery of pet store purchase receipts. Some activists attempted to intercept owners who were on their way to turn in pet hamsters and encourage them to choose adoption instead, which the government subsequently warned would be subject to police action.
Hamsters as lab animals
The extracted cells of babies' kidneys and adults' ovaries are used to study cholesterol synthesis
The mevalonate pathway, also known as the isoprenoid pathway or HMG-CoA reductase pathway is an essential metabolic pathway present in eukaryotes, archaea, and some bacteria. The pathway produces two five-carbon building blocks called isopenten ...
.[ ]
Similar animals
Some similar rodents sometimes called "hamsters" are not currently classified in the hamster subfamily Cricetinae. These include the maned hamster, or crested hamster, which is really the maned rat
The maned rat or (African) crested rat (''Lophiomys imhausi'') is a nocturnal, long-haired and bushy-tailed East African rodent that superficially resembles a porcupine. The world's only poisonous rodent, the maned rat borrows toxins from plants ...
(''Lophiomys imhausi''). Others are the mouse-like hamster
200px, right
200px, Mouse-like hamster using its tail for balance while standing on a branch (a feat difficult for hamsters)
Mouse-like hamsters are a group of small rodents found in Syria, Azerbaijan, Iran, Turkmenistan, Afghanistan, and Pakis ...
s (''Calomyscus'' spp.), and the white-tailed rat
The white-tailed rat (''Mystromys albicaudatus'') also known as the white-tailed mouse, is the only member of the subfamily Mystromyinae in the family Nesomyidae. This species is sometimes placed in the subfamily Cricetinae due to similarities ...
(''Mystromys albicaudatus'').
See also
* Syrian hamster care
Syrian hamster care includes all the actions which a person might take to promote animal welfare in the Syrian hamster when it lives with humans either as a pet or laboratory animal.
Enclosure
There are some different recommendations for what ...
* Hamster cage
A hamster cage is a cage designed to house a hamster or hamsters. Hamster cages need to be at least 1524 cm2 (600 in2) of floor space or bigger, although many experts such as Gernot Kuhnen recommend that hamsters thrive with larger cage sizes. ...
* Hamster show
A hamster show is an event in which people gather hamsters to judge them against each other. Hamster shows are also places where people share their enthusiasm for hamsters among attendees. Hamster shows feature an exhibition of the hamsters partic ...
* Hamster wheel
A hamster wheel or running wheel is an exercise device used primarily by hamsters and other rodents, but also by other cursorial animals when given the opportunity. Most of these devices consist of a runged or ridged wheel held on a stand by a ...
* Hamster ball
Hamster balls are hollow spheres made of clear plastic into which hamsters, gerbils, degus and other small rodent pets are placed, allowing them to run around outside their cages without the risk of running away or getting lost under furniture. ...
* Chinchilla
Chinchillas are either of two species (''Chinchilla chinchilla'' and ''Chinchilla lanigera'') of crepuscular rodents of the parvorder Caviomorpha. They are slightly larger and more robust than ground squirrels, and are native to the Andes mount ...
* ''Ebichu
is a Japanese manga series by Risa Itō that was published by Futabasha Publishers. It first ran through Shufutoseikatsusha magazine ''Giga&chan'', beginning in the 1990 and next moving to ''Action Pizazz'', publication by Futabasha.
It wa ...
''
* Gerbil
The Mongolian gerbil or Mongolian jird (''Meriones unguiculatus'') is a small rodent belonging to the subfamily Gerbillinae. Their body size is typically , with a tail, and body weight , with adult males larger than females. The animal is use ...
* Guinea pig
The guinea pig or domestic guinea pig (''Cavia porcellus''), also known as the cavy or domestic cavy (), is a species of rodent belonging to the genus ''Cavia'' in the family Caviidae. Breeders tend to use the word ''cavy'' to describe the ani ...
, a similar species
* Hampster Dance
The Hampster Dance is one of the earliest Internet memes. Created in 1998 by Canadian art student Deidre LaCarte as a GeoCities page, the dance features rows of animated GIFs of hamsters and other rodents dancing in various ways to a sped-up ...
* Hamster racing
Hamster racing is a sport in which hamsters are placed in hamster wheels or hamster balls – often fitted to miniature racing vehicles – and raced down a straight 9 meter (30 ft) course. The hamster crossing the finish line in the shorte ...
* ''Hamtaro
''Hamtaro'', known in Japan as , is a Japanese manga and storybook series created and illustrated by Ritsuko Kawai about a hamster. The manga was serialized in Shogakukan's "Second Grade" magazine in April 1997; more ''Hamtaro'' stor ...
''
* Rat
References
External links
National Hamster Council (UK)
{{Authority control
Cricetidae
Articles containing video clips
Extant Miocene first appearances
Taxa named by Gotthelf Fischer von Waldheim