{{Short description|Species of hamster}} {{Use dmy dates|date=April 2020}} {{Speciesbox | image = Golden_hamster_front_1.jpg | image_caption = A domestic female golden hamster | status = EN | status_system = IUCN3.1 | status_ref = <ref name="iucn status 19 November 2021">{{cite iucn |author= Kennerley, R. |author2=Middleton, K.|date=2022 |title=''Mesocricetus auratus'' |volume=2022 |article-number=e.T13219A107411865 |url=https://www.iucnredlist.org/species/13219/107411865 |access-date=21 July 2022}}</ref> | genus = Mesocricetus | species = auratus | authority = ([[George Robert Waterhouse|Waterhouse]], 1839) | synonyms = ''Cricetus auratus'' <small>Waterhouse, 1839</small> }}
The '''golden hamster''' or '''Syrian hamster''' ('''''Mesocricetus auratus''''') is a [[rodent]] belonging to the hamster [[subfamily]], [[Cricetinae]].<ref name = MSW3>{{MSW3 Muroidea | id = 13000364 | page = 1044}}</ref> Their natural geographical range is in an [[Arid|arid region]] of northern [[Syria]] and southern [[Turkey]]. Their numbers have been declining in the wild due to a [[Habitat destruction|loss of habitat]] from agriculture and deliberate elimination by humans.<ref name="iucn status 19 November 2021" /> Thus, wild golden hamsters are now considered endangered by the [[IUCN|International Union for Conservation of Nature]].<ref>{{Cite web|url=https://www.iucnredlist.org/en|title=The IUCN Red List of Threatened Species – Golden Hamster|website=IUCN Red List of Threatened Species|access-date=2019-04-11}}</ref> However, [[captive breeding program]]s are well established, and captive-bred golden hamsters are often kept as [[Small pets|small house pets]]. They are also used as [[Animal research|scientific research animals]].
Syrian hamsters are larger than many of the [[Phodopus|dwarf hamsters]] kept as pocket pets (up to five times larger), though the wild [[European hamster]] exceeds Syrian hamsters in size.
== Characteristics ==
[[File:Mesocricetus auratus 02 MWNH 1067.jpg|thumb|Skull of a golden hamster]] Adult golden hamsters can reach around {{convert|7.1|in|cm|abbr=on}} long. Females are usually larger than males, with a body mass of around {{Convert|100–150|g||abbr=}} and lifespan of 1.5–2 years. Syrian hamsters from private breeders can be in the range of {{Convert|175–225|g||abbr=}}.<ref name = "Svenska hamsterföreningen">{{cite web | title = Guldhamster | website = Svenska Hamsterföreningen | url = http://www.hamsterforeningen.se/v%C3%A5ra-arter/guldhamster-1895075 | access-date = 2020-06-16 }}</ref>
[[File:GoldenHamster.jpg|thumb|left|upright=0.7|Male golden hamster standing up]] Like most members of the subfamily, the golden hamster has expandable [[cheek pouch]]es, which extend from its cheeks to its shoulders. In the wild, hamsters are larder hoarders; they use their cheek pouches to transport food to their burrows. Their name in the local [[Arabic language|Arabic]] dialect where they were found roughly translates to "mister saddlebags" ({{Langx|ar|أبو جراب|links=no}}) due to the amount of storage space in their cheek pouches.<ref>{{cite web |first=Rob |last=Dunn |title=The Untold Story of the Hamster, a.k.a Mr. Saddlebags |publisher=Smithsonianmag.com |date=24 March 2011 |url=http://www.smithsonianmag.com/science-nature/the-untold-story-of-the-hamster-aka-mr-saddlebags-1223774/}}</ref>
Sexually mature female hamsters come into heat ([[estrus]]) every four days. Golden hamsters and other species in the genus ''[[Mesocricetus]]'' have the shortest [[gestation]] period in any known [[placental mammal]] at around 16 days. Gestation has been known to last up to 21 days, but this is rare and almost always results in complications. They can produce large litters of 20 or more young, although the average litter size is between eight and 10 pups. If a mother hamster is inexperienced or feels threatened, she may abandon or [[Infanticide (zoology)|eat her pups]]. A female hamster enters estrus almost immediately after giving birth, and can become pregnant despite already having a litter. This act puts stress on the mother's body and often results in very weak and undernourished young.{{citation needed|date=June 2019}}
== Discovery ==
{{main|Domestication of the Syrian hamster}} Golden hamsters originate from Syria and were first described by scientists in the 1797 second edition of ''[[The Natural History of Aleppo]]'', a book written and edited by two Scottish physicians living in Syria.<ref>{{cite book|last1=Murphy|first1=Michael R.|editor1-last=Siegel|editor1-first=Harold I.|title=The Hamster: reproduction and behavior|date=1985|publisher=Plenum Press|location=New York|isbn=0-306-41791-X|chapter=History of the Capture and Domestication of the Syrian Golden Hamster (Mesocricetus auratus Waterhouse)}}</ref> The Syrian hamster was then recognized as a distinct species in 1839 by British zoologist [[George Robert Waterhouse]], who named it ''Cricetus auratus'' or the "golden hamster". The skin of the [[holotype]] specimen is kept at the [[Natural History Museum, London|Natural History Museum]] in London.<ref name="discovery">{{cite journal|last=Henwood|first=Chris|year=2001|title=The Discovery of the Syrian Hamster, ''Mesocricetus auratus''|url=https://www.britishhamsterassociation.org.uk/get_article.php?fname=journal/discover_syrian.html|archive-url=https://web.archive.org/web/20190403211735/https://www.britishhamsterassociation.org.uk/get_article.php?fname=journal%2Fdiscover_syrian.html|archive-date=3 April 2019|journal=The Journal of the British Hamster Association|issue=39|url-status=usurped|access-date=27 August 2020}}</ref>
In 1930, [[Israel Aharoni]], a zoologist and professor at the [[Hebrew University of Jerusalem]], captured a mother hamster and her litter of pups in [[Aleppo]], Syria. The hamsters were bred in Jerusalem as laboratory animals.
Descendants of the captive hamsters were shipped to Britain in 1931, where they came under the care of the Wellcome Bureau of Scientific Research. These bred and two more pairs were given to the [[Zoological Society of London]] in 1932. The descendants of these were passed on to private breeders in 1937.
In 1946, Albert Marsh began the first commercial hamster breeding business, [[Gulf Hamstery]], to promote the Syrian hamster as pets and laboratory animals.<ref>{{cite book|last1=Murphy|first1=Michael R.|editor1-last=Siegel|editor1-first=Harold I.|title=The Hamster: reproduction and behavior|date=1985|publisher=Plenum Press|location=New York|isbn=0-306-41791-X|chapter=History of the Capture and Domestication of the Syrian Golden Hamster (Mesocricetus auratus Waterhouse)}}</ref>
A separate stock of hamsters was exported from Syria to the United States in 1971, but [[mitochondrial DNA]] studies have established that all domestic golden hamsters are descended from one female – likely the one captured in 1930 in Syria.<ref>{{cite book |last1=Sykes |first1=Brian |title=The Seven Daughters of Eve: The Science That Reveals Our Genetic Ancestry |date=2001 |publisher=W. W. Norton & Company |isbn=978-0-00-712282-0 |pages=57–62}}</ref>
Since the species was named, the genus ''Cricetus'' has been subdivided and this species (together with several others) was separated into the genus ''Mesocricetus'', leading to the currently accepted scientific name for the golden hamster of ''Mesocricetus auratus''.<ref name="MSW3a">{{MSW3|id=13000363|heading=''Mesocrictus''}}</ref>
== Behavior == A solitary species, Syrian hamsters are very territorial and intolerant of each other; attacks against each other are commonplace. Exceptions do occur, usually when a female and male meet when the female is in heat, but even so, the female may attack the male after mating. In captivity, babies are separated from their mother and by sex after four weeks, as they sexually mature at four to five weeks old. Same-sex groups of siblings can stay with each other until they are about eight weeks old, at which point they will become territorial and fight with one another, sometimes to the death. [[Infanticide (zoology)|Infanticide]] is not uncommon among female golden hamsters. In captivity, they may kill and eat healthy young as a result of the pups interacting with humans, as any foreign scent is treated as a threat. Females also eat their dead young in the wild.<ref name="SiegelRosenblatt1980">{{cite journal|last1=Siegel|first1=Harold I.|last2=Rosenblatt|first2=Jay S.|title=Hormonal and behavioral aspects of maternal care in the hamster: A review|journal=Neuroscience & Biobehavioral Reviews|volume=4|issue=1|year=1980|pages=17–26|issn=0149-7634|doi=10.1016/0149-7634(80)90023-8|pmid=6995872|s2cid=10591609}}</ref>
Golden hamsters mark their burrows with secretions from special scent glands on their hips called [[flank gland]]s. Male hamsters in particular lick their bodies near the glands, creating damp spots on the fur, then drag their sides along objects to mark their territory. Females also use bodily secretions and feces.
=== Socialization ===
Syrian hamsters acquire [[learned helplessness]] when they are [[Bullying|bullied]] a few times by a larger animal.<ref name="PotegalHuhman1993">{{cite journal|last1=Potegal|first1=M.|last2=Huhman|first2=K.|last3=Moore|first3=T.|last4=Meyerhoff|first4=J.|title=Conditioned defeat in the Syrian golden hamster (Mesocricetus auratus)|journal=Behavioral and Neural Biology|volume=60|issue=2|year=1993|pages=93–102|issn=0163-1047|doi=10.1016/0163-1047(93)90159-F|pmid=8117243}}</ref> They can regain lost confidence if they are not bullied for some time.<ref name="PotegalHuhman1993"/>
Interactions between male and female Syrian hamsters are influenced by the [[estrous cycle]] - in addition, their behavior changes over the course of the four-day cycle. Parameters for interactions that have been studied include sniffing, approaching, leaving, and following each other (male/female pair).<ref>{{Cite journal|last=Steel|first=E.|date=February 1980|title=Changes in female attractivity and proceptivity throughout the oestrous cycle of the Syrian hamster (Mesocricetus auratus)|journal=Animal Behaviour|volume=28 Pt 1|pages=256–265|issn=0003-3472|pmid=7194608|doi=10.1016/s0003-3472(80)80028-5|s2cid=22001121}}</ref> Specific to the male hamster, his response to the female can be measured by mounting behavior, intromission and ejaculation.<ref>{{Cite journal|last=Steel|first=E.|date=December 1982|title=Testosterone-dependent non-copulatory behaviour in male hamsters (Mesocricetus auratus)|journal=The Journal of Endocrinology|volume=95|issue=3|pages=387–396|issn=0022-0795|pmid=6890981|doi=10.1677/joe.0.0950387}}</ref>
Under semi-natural conditions, the mating behaviors of male and female hamsters were observed over the four days of the estrous cycle.<ref name=":0">{{Cite journal|date=1983-08-01|title=Mating behaviour of the golden hamster under seminatural conditions|journal=Animal Behaviour|language=en|volume=31|issue=3|pages=659–666|doi=10.1016/S0003-3472(83)80221-8|issn=0003-3472|last1=Lisk|first1=Robert D.|last2=Ciaccio|first2=Leonard A.|last3=Catanzaro|first3=Cathy|s2cid=53204698}}</ref> When allowed free interaction, females displayed [[Lordosis behavior|lordosis]] in their own living area 93% of the time. After 60 minutes of copulation, the female would force the male out while she retrieved his food supply and aggressively forced him into the corner farthest away from her nest.<ref name=":0" />
When a Syrian hamster is introduced to a new hamster in its own cage, it performs a [[fixed action pattern]] consisting of a sequence of acts and postures that are [[Agonistic behaviour|agonistic]] by nature.<ref name=":5">{{Cite journal|date=1971-11-01|title=The agonistic behaviour of the golden hamster Mesocricetus auratus (waterhouse)|journal=Animal Behaviour|language=en|volume=19|issue=4|pages=714–721|doi=10.1016/S0003-3472(71)80175-6|issn=0003-3472|last1=Lerwill|first1=C.J.|last2=Makings|first2=P.}}</ref> It has been observed from posture that one hamster becomes dominant and the other submissive;<ref name=":5" /> it is usually the new hamster that emerges dominant.<ref name=":5" />
=== Feeding === [[File:Cheeks.JPG|thumb|Golden hamster filling its cheek pouches with food]] Under typical laboratory conditions, Syrian hamsters apparently do not exhibit food-anticipatory activity (FAA){{snd}}that is, when on a restricted feeding schedule where food is given at specific times of day, they do not demonstrate increased [[Hamster wheel|wheel-running]] prior to feeding time.<ref name="FAA"/> This is in contrast to most other rodents.<ref name="FAA"/> However, standard laboratory conditions include bright light during the daytime; when subjected to a light cycle simulating dawn and dusk with darkness during the day, they do exhibit the behavior.<ref name="FAA">{{cite journal | doi = 10.1371/journal.pone.0126519 | pmid = 25970608 | pmc = 4430487 | bibcode = 2015PLoSO..1026519D | title = Food-anticipatory activity in Syrian hamsters: Behavioral and molecular responses in the hypothalamus according to photoperiodic conditions | year = 2015 | last1 = Dantas-Ferreira | first1 = Rosana F. | last2 = Dumont | first2 = Stéphanie | last3 = Gourmelen | first3 = Sylviane | last4 = Cipolla-Neto | first4 = José | last5 = Simonneaux | first5 = Valérie | last6 = Pévet | first6 = Paul | last7 = Challet | first7 = Etienne | journal = PLOS ONE | volume = 10 | issue = 5 | article-number = e0126519 | doi-access = free }}</ref> The [[Arcuate nucleus (hypothalamus)|arcuate]], [[Ventromedial nucleus of the hypothalamus|ventromedial]] and [[Dorsomedial hypothalamic nucleus|dorsomedial nuclei]] are all involved in FAA in Syrian hamsters.<ref name="FAA"/>
In a study of their food-hoarding behavior, Syrian hamsters were given access to food for only limited periods of time. It was expected that they would consume more in each sitting than usual;<ref name=":6">{{Cite journal | url=https://www.tandfonline.com/doi/abs/10.1080/14640748908401182 | doi=10.1080/14640748908401182| pmid=2710941| title=Food hoarding behaviour in the golden hamster (''Mesocricetus auratus''): Effects of body weight loss and hoard-size discrimination| journal=The Quarterly Journal of Experimental Psychology Section B| volume=41| issue=1| pages=33–47| date=February 1989| last1=Phillips| first1=John H.| last2=Davey| first2=Graham C. L.| last3=Robinson| first3=Angelina| doi-broken-date=12 July 2025}}</ref> instead, they exhibited hoarding behavior, taking the food during the given time period and then continuously eating it the rest of the time as though they were on a free-fed schedule.<ref name=":6" /> This allowed them to maintain typical body weight, and mimic the adaptive feeding strategies they may use in their natural habitats.
Females have shown signs of [[anorexia]] and [[anxiety]] when separated from social interactions.<ref name=":02">{{Cite journal|last1=Shannonhouse|first1=John L.|last2=Fong|first2=Li An|last3=Clossen|first3=Bryan L.|last4=Hairgrove|first4=Ross E.|last5=York|first5=Daniel C.|last6=Walker|first6=Benjamin B.|last7=Hercules|first7=Gregory W.|last8=Mertesdorf|first8=Lauren M.|last9=Patel|first9=Margi|date=June 2014|title=Female-biased anorexia and anxiety in the Syrian hamster|journal=Physiology & Behavior|volume=133|pages=141–151|doi=10.1016/j.physbeh.2014.05.019|pmid=24866911|s2cid=30484883|issn=0031-9384}}</ref> Social separation of hamsters has a bias toward females, thus providing a model for the differences between sexes when experiencing anorexia and anxiety in their adulthood.<ref name=":02" />
=== Sleep === [[File:Burrowing_Hamster.jpg|thumb|upright=0.8|Syrian hamster burrowed in its bedding]]
The [[sleep cycle]] of the Syrian hamster lasts approximately 10–12 minutes.<ref>{{Cite journal|date=1995-07-01|title=Is sleep fundamentally different between mammalian species?|journal=Behavioural Brain Research|language=en|volume=69|issue=1–2|pages=35–41|doi=10.1016/0166-4328(95)00025-O|pmid=7546316|issn=0166-4328|last1=Tobler|first1=Irene|s2cid=4048560}}</ref>
In the laboratory, Syrian hamsters are observed to be [[Nocturnality|nocturnal]] and in their natural [[circadian rhythm]] they wake and sleep on a consistent schedule.<ref name="GattermannJohnston2008">{{cite journal|last1=Gattermann|first1=R.|last2=Johnston|first2=R. E.|last3=Yigit|first3=N.|last4=Fritzsche|first4=P.|last5=Larimer|first5=S.|last6=Ozkurt|first6=S.|last7=Neumann|first7=K.|last8=Song|first8=Z.|last9=Colak|first9=E.|last10=Johnston|first10=J.|last11=McPhee|first11=M. E.|title=Golden hamsters are nocturnal in captivity but diurnal in nature|journal=Biology Letters|volume=4|issue=3|year=2008|pages=253–255|issn=1744-9561|doi=10.1098/rsbl.2008.0066|pmid=18397863|pmc=2610053}}</ref> In all kinds of laboratory settings hamsters do 80% of their routine activities at night.<ref name="PrattGoldman1986">{{cite journal|last1=Pratt|first1=Barbara L.|last2=Goldman|first2=Bruce D.|title=Activity rhythms and photoperiodism of syrian hamsters in a simulated burrow system|journal=Physiology & Behavior|volume=36|issue=1|year=1986|pages=83–89|issn=0031-9384|doi=10.1016/0031-9384(86)90078-8|pmid=3952187|s2cid=41807306}}</ref> They are most active early in the night, and become less active as the night passes.<ref name="GattermannJohnston2008" />
The sleeping behavior of wild hamsters is not well understood;<ref name="GattermannJohnston2008"/> a study found that in the wild, Syrian hamsters are active almost exclusively during the daytime, contrary to observations in the laboratory.<ref name="GattermannJohnston2008"/>
=== Reproduction === [[File:Syrian hamster - mating.jpg|thumb|Syrian hamsters mating]] The female Syrian hamster has anatomic features that are unique from other animals. They mature between 8–10 weeks of age and have a 4-day [[estrous cycle]].<ref>{{cite journal | doi = 10.1177/0192623315607668 | pmid = 26516162 | title = The Syrian Golden Hamster Estrous Cycle: Unique Characteristics, Visual Guide to Staging, and Comparison with the Rat | year = 2016 | last1 = Chanut | first1 = Franck J. A. | last2 = Williams | first2 = Ann M. | journal = Toxicologic Pathology | volume = 44 | issue = 1 | pages = 43–50 | s2cid = 7987077 | doi-access = free }}</ref>
Female Syrian hamsters show mate preference before they engage in [[copulation (zoology)|copulation]] by displaying vaginal marking, known to solicit males.<ref name=":1">{{Cite journal|date=1985-09-01|title=Scent marking and mate choice in the golden hamster|journal=Physiology & Behavior|language=en|volume=35|issue=3|pages=389–393|doi=10.1016/0031-9384(85)90314-2|pmid=4070412|issn=0031-9384|last1=William Huck|first1=U.|last2=Lisk|first2=Robert D.|last3=Gore|first3=Andrea C.|s2cid=22230079}}</ref> She often chooses to mate with an alpha male, who will flank mark (a [[scent marking|scent-marking]] behavior associated with aggression and competition<ref>{{Cite journal|date=1998-08-01|title=Kin recognition in golden hamsters: evidence for phenotype matching|journal=Animal Behaviour|language=en|volume=56|issue=2|pages=409–417|doi=10.1006/anbe.1998.0747|pmid=9787032|issn=0003-3472|last1=Heth|first1=Giora|last2=Todrank|first2=Josephine|last3=Johnston|first3=Robert E.|s2cid=32973084}}</ref>) more frequently than any subordinate males present.<ref name=":1" />
Male offspring are at higher risk than female offspring of enduring effects from maternal [[social stress]].<ref name=":2">{{Cite journal|last1=Pratt|first1=N. C.|last2=Lisk|first2=R. D.|date=1989-11-01|title=Effects of social stress during early pregnancy on litter size and sex ratio in the golden hamster (Mesocricetus auratus)|url=https://rep.bioscientifica.com/view/journals/rep/87/2/jrf_87_2_038.xml|journal=Reproduction|language=en-US|volume=87|issue=2|pages=763–769|doi=10.1530/jrf.0.0870763|pmid=2600923|issn=1470-1626|doi-access=free|url-access=subscription}}</ref> In the presence of a dominant pregnant female, subordinate pregnant female hamsters have the ability to reabsorb or spontaneously abort their young (most often males) ''in utero.''<ref name=":2" /> The subordinate females produce smaller litters overall, and any male offspring they do produce will be smaller in size than those that were produced by the dominant female.<ref name=":2" /> After a mother hamster gives birth, normal behavior from the mother in the [[postpartum period]] can include establishing a [[maternal bond]] with the babies, the mother being aggressive to protect the babies, or [[infanticide in rodents]] of the mother to her young.<ref name="SiegelRosenblatt1980">{{cite journal|last1=Siegel|first1=Harold I.|last2=Rosenblatt|first2=Jay S.|title=Hormonal and behavioral aspects of maternal care in the hamster: A review|journal=Neuroscience & Biobehavioral Reviews|volume=4|issue=1|year=1980|pages=17–26|issn=0149-7634|doi=10.1016/0149-7634(80)90023-8|pmid=6995872|s2cid=10591609}}</ref>
The male Syrian hamster has a requirement for both hormonal cues and chemosensory cues in order to engage in copulation. Further, the integration of steroid cues (i.e. testosterone) and odour cues (relayed through the [[olfactory bulb]]) is crucial for mating.<ref>{{Cite journal|date=1997-04-14|title=Integration of chemosensory and hormonal cues is essential for sexual behaviour in the male syrian hamster: role of the medial amygdaloid nucleus|journal=Neuroscience|language=en|volume=78|issue=4|pages=1027–1035|doi=10.1016/S0306-4522(96)00629-X|pmid=9174071|issn=0306-4522|last1=Wood|first1=R.I|last2=Coolen|first2=L.M|s2cid=38844348|doi-access=free}}</ref> It has also been shown that within the medial amygdala, the anterior and posterior regions work together to process the stimuli (odors), showing that their mating behavior relies on the main olfactory system's communication to nuclei in the amygdala regions.<ref>{{Cite journal|last1=Maras|first1=P. M.|last2=Petrulis|first2=A.|date=2010-02-17|title=Lesions that functionally disconnect the anterior and posterodorsal sub-regions of the medial amygdala eliminate opposite-sex odor preference in male Syrian hamsters (Mesocricetus auratus)|journal=Neuroscience|volume=165|issue=4|pages=1052–1062|doi=10.1016/j.neuroscience.2009.11.024|issn=1873-7544|pmc=2814983|pmid=19931356}}</ref> Their behavior has demonstrated this phenomenon, as they are attracted to the odor of female hamster's vaginal discharge.<ref name=":3">{{Cite journal|date=1973-09-01|title=Effects of female hamster vaginal discharge on the behavior of male hamsters|journal=Behavioral Biology|language=en|volume=9|issue=3|pages=367–375|doi=10.1016/S0091-6773(73)80185-3|pmid=4795496|issn=0091-6773|last1=Murphy|first1=Michael R.}}</ref> Males have even demonstrated mounting behavior on other males who are scented with the female vaginal discharge.<ref name=":3" />
When one male and two females are placed in the same environment, the male is likely to engage in copulation with both females as it provides him with a [[reproductive advantage]].<ref name=":4">{{Cite journal|last1=Dewsbury|first1=Donald A.|last2=Lanier|first2=David L.|last3=Oglesby|first3=Joseph M.|date=December 1979|title=Copulatory behavior of Syrian golden hamsters in a one-male two-female test situation|journal=Animal Learning & Behavior|language=en|volume=7|issue=4|pages=543–548|doi=10.3758/bf03209716|s2cid=144582540|issn=0090-4996|doi-access=free}}</ref> In all observed scenarios where there was one male and two females, he did not demonstrate preference for either female and engaged in copulation with both the females present.<ref name=":4" /> There has been no reproductive disadvantage to the female when another female is present, other than decreased stimulation as compared to a one-male one-female situation.<ref name=":4" />
=== In captivity ===
Gnawing at cage wires is considered an indicator of reduced welfare in captive Syrian hamsters.<ref name=":8"/> Almost all hamsters display wire-gnawing behavior in laboratory cages, regardless of cage size, but gnawing increases as cage size decreases.<ref name=":7">K Fischer, SG Gebhardt-Henrichand & A Steiger (2007). Behaviour of golden hamsters (Mesocricetus auratus) kept in four different cage sizes. ''Animal Welfare.''</ref> Additionally, a hamster in a smaller cage will use the roof of their house as a platform more often than a hamster in a larger cage, which may suggest they feel the need to use the extra space when floor space is restricted.<ref name=":7" />
In three groups of hamsters housed with 10, 40 and 80 cm of bedding, those with 10 cm of bedding exhibited significantly more wire-gnawing than the other two groups, and generally did not construct their own burrows (preferring to sleep in pre-made shelters).<ref name=":8"/> All hamsters with 40 or 80 cm of bedding constructed and used burrows similar to those built by wild Syrian hamsters.<ref name=":8"/> Animals in the 40 cm group showed minimal wire-gnawing, and those in the 80 cm group did not gnaw the wires at all.<ref name=":8">{{Cite journal|date=2006-11-01|title=The influence of bedding depth on behaviour in golden hamsters (Mesocricetus auratus)|journal=Applied Animal Behaviour Science|language=en|volume=100|issue=3–4|pages=280–294|doi=10.1016/j.applanim.2005.11.012|issn=0168-1591|last1=Hauzenberger|first1=Andrina R.|last2=Gebhardt-Henrich|first2=Sabine G.|last3=Steiger|first3=Andreas}}</ref>
== Survival in the wild ==
Following Professor Aharoni's collection in 1930, only infrequent sightings and captures were reported in the wild. Finally, to confirm the current existence of the wild golden hamster in northern Syria and southern Turkey, two expeditions were carried out in September 1997 and March 1999. The researchers found and mapped 30 burrows. None of the inhabited burrows contained more than one adult. The team caught six females and seven males. One female was pregnant and gave birth to six pups. All these 19 caught golden hamsters, together with three wild individuals from the University of Aleppo, were shipped to Germany to form a new breeding stock.<ref name="Gattermann">{{cite journal|last1=Gattermann|first1= R.|year= 2001|title=Notes on the current distribution and the ecology of wild golden hamsters (''Mesocricetus auratus'')|journal= Journal of Zoology|volume= 254|pages= 359–365 |publisher=Cambridge University Press|url=http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=78463|doi=10.1017/S0952836901000851|last2=Fritzsche|first2=P.|last3=Neumann|first3=K.|last4=Al-Hussein|first4=I.|last5=Kayser|first5=A.|last6=Abiad|first6=M.|last7=Yakti|first7=R.|issue=3|bibcode= 2001JZoo..254..359G|url-access=subscription}}</ref>
Observations of females in this wild population have revealed, contrary to laboratory populations, that activity patterns are [[crepuscular]] rather than [[nocturnal]], possibly to avoid nocturnal predators such as [[owl]]s.<ref>{{cite journal|last1=Gattermann|first1= R.|last2=Johnston|first2= R. E.|year=2008|title= Syrian hamsters are nocturnal in captivity but diurnal in nature|journal=Biology Letters |volume=4|pages= 253–255|doi=10.1098/rsbl.2008.0066|pmid=18397863|last3=Yigit|first3=N|last4=Fritzsche|first4=P|last5=Larimer|first5=S|last6=Ozkurt|first6=S|last7=Neumann|first7=K|last8=Song|first8=Z|last9=Colak|first9=E|last10= Johnston|first10= J.|last11= McPhee|first11= M. E.|issue=3|pmc=2610053|display-authors= 8}}</ref>
== As research animals == [[File:Gait-of-healthy-Hamster.ogv|thumb|300px|Video showing the [[gait]] of a [[Laboratory|lab]]-bred hamster from the underside]] {{main|Laboratory Syrian hamster}}Golden hamsters are used to model human medical conditions including various [[cancer]]s, metabolic diseases, non-cancer respiratory diseases, cardiovascular diseases, [[infectious disease]]s, and general health concerns.{{sfn|Valentine|Daugherity|Singh|Maurer|2012|p=875-898}} In 2006 and 2007, golden hamsters accounted for 19% of the total Animal Welfare Act-covered [[animal research]] subjects in the United States.<ref name="2007 USDA">{{Citation |author=United States Department of Agriculture |date=September 2008 |title=Animal Care Annual Report of Activities – Fiscal Year 2007 |publisher=United States Department of Agriculture |url=https://ourcompass.files.wordpress.com/2010/06/2007_ac_report.pdf |access-date=14 January 2016 }}</ref> They have also been studied as models for the development of the palate and incidence of cleft palate,<ref>{{Cite journal|last1=Shah|first1=R M|last2=Chaudhry|first2=A P|date=February 1974|title=Light microscopic and histochemical observations on the development of the palate in the Golden Syrian hamster.|journal=Journal of Anatomy|volume=117|issue=Pt 1|pages=1–15|issn=0021-8782|pmc=1231429|pmid=4844648}}</ref><ref>{{Cite journal|last1=Shah|first1=RM|last2=Arcadi|first2=F|last3=Suen|first3=R|last4=Burdett|first4=DN|date=1989|title=Effects of cyclophosphamide on the secondary palate development in golden Syrian hamster: teratology, morphology, and morphometry.|journal=Journal of Craniofacial Genetics and Developmental Biology|language=en|volume=9|issue=4|pages=381–96|issn=0270-4145|pmid=2634683}}</ref> the influence of retinoic acid on physical malformations in fetuses,<ref>{{Cite journal|last=Wiley|first=M. J.|date=December 1983|title=The pathogenesis of retinoic acid-induced vertebral abnormalities in golden Syrian hamster fetuses|journal=Teratology|language=en|volume=28|issue=3|pages=341–353|doi=10.1002/tera.1420280306|pmid=6665734|issn=0040-3709}}</ref> immune responses to diseases like hookworm,<ref>{{Cite journal|last1=Mendez|first1=Susana|last2=Valenzuela|first2=Jesus G.|last3=Wu|first3=Wenhui|last4=Hotez|first4=Peter J.|date=2005-06-01|title=Host Cytokine Production, Lymphoproliferation, and Antibody Responses during the Course of Ancylostoma ceylanicum Infection in the Golden Syrian Hamster|journal=Infection and Immunity|language=en|volume=73|issue=6|pages=3402–3407|doi=10.1128/IAI.73.6.3402-3407.2005|issn=0019-9567|pmid=15908367|pmc=1111885}}</ref> and the effects of ingesting ethanol solution on liver composition and fatty acid accumulation.<ref>{{Cite journal|last1=Cunnane|first1=S.C.|last2=Manku|first2=M·S.|last3=Horrobin|first3=D.F.|date=1985|title=Effect of Ethanol on Liver Triglycerides and Fatty Acid Composition in the Golden Syrian Hamster|journal=Annals of Nutrition and Metabolism|language=english|volume=29|issue=4|pages=246–252|doi=10.1159/000176977|pmid=4026205|issn=1421-9697}}</ref>
[[Rocky Mountain Laboratories]] used Syrian hamsters for disease transmission research.<ref>{{cite journal |last=de Wit |first=E. |date=2011 |title=Nipah virus transmission in a hamster model |journal=PLOS |volume=5 |issue=12 |article-number=e1432 |doi=10.1371/journal.pntd.0001432 |pmid=22180802 |pmc=3236726 |doi-access=free }}</ref> [[SARS-CoV-2]] transmits efficiently in Syrian hamsters.<ref>{{cite journal |last1=Yinda |first1=C. |date=9 Jan 2024 |title=Airborne transmission efficiency of SARS-CoV-2 in Syrian hamsters is not influenced by environmental conditions |journal=Nature |volume=2 |issue=1 |article-number=2 |doi=10.1038/s44298-023-00011-3 |pmid=40295780 |pmc=11702665 }}</ref>
== As pets ==
[[File:Syrian Hamster 2.JPG|thumb|A golden hamster listening from its plastic [[Hamster wheel|exercise wheel]] | alt=|left]] [[File:Juvenile Female Mesocricetus auratus in Pet Store enclosure, Illinois, USA.jpg|upright=0.7|alt=A young, brown female hamster for sale in a Pet Store in the United States|thumb|A young female golden hamster for sale at a pet store in the United States]] Golden hamsters are popular as house pets due to their docile, inquisitive nature, cuteness, and small size. However, these animals have some special requirements that must be met for them to be healthy. Although some people think of them as a pet for young children, the [[American Society for the Prevention of Cruelty to Animals]] recommends hamsters as pets only for people over age 6 and the child should be supervised by an adult.<ref>{{cite web |url=https://www.aspca.org/sites/default/files/upload/images/hamster_edu.pdf |title=Hamster Care |date=2010 |publisher=American Society for the Prevention of Cruelty to Animals |access-date=23 December 2016 |archive-date=5 June 2021 |archive-url=https://web.archive.org/web/20210605054712/https://www.aspca.org/sites/default/files/upload/images/hamster_edu.pdf }}</ref> Cages should be a suitable size, safe, comfortable, and interesting. If a hamster is constantly chewing or climbing on the bars of its cage, then it needs more stimulation or a larger enclosure. The recommended size for a hamster cage is {{convert|1|m2|sqin|abbr=}}, of continuous floor space or larger.<ref>{{cite journal |last1=Fischer |first1=K |last2=Gebhardt-Henrich |first2=Sg |last3=Steiger |first3=A |title=Behaviour of golden hamsters (Mesocricetus auratus) kept in four different cage sizes |journal=Animal Welfare |date=February 2007 |volume=16 |issue=1 |pages=85–93 |doi=10.1017/S0962728600030967 |url=https://www.cambridge.org/core/journals/animal-welfare/article/abs/behaviour-of-golden-hamsters-mesocricetus-auratus-kept-in-four-different-cage-sizes/EE15E6061289B1B278F0CD77281F7FF4 |access-date=3 August 2024|url-access=subscription }}</ref> These can be made by cutting and connecting large plastic storage bins, or by using a large glass [[aquarium]]. Appropriately sized wooden enclosures can be made, or bought online. The majority of hamster cages sold in pet stores do not meet these size requirements.{{citation needed|date=November 2024}} Hamster Society Singapore (HHS) recommends a minimum of {{Convert|4000|cm2||abbr=}} for Syrian hamsters,<ref>{{Cite web |url=https://www.hamstersociety.sg/hamster-care-blog/2019/2/17/hamster-cages-part-1 |title=Hamster Society Singapore |access-date=1 April 2020 |archive-date=16 July 2022 |archive-url=https://web.archive.org/web/20220716160223/https://www.hamstersociety.sg/hamster-care-blog/2019/2/17/hamster-cages-part-1 |url-status=dead }}</ref> while Tierärztliche Vereinigung für Tierschutz (TVT) recommends giving them as much space as you can and at minimum 100 cm × 50 cm × 50 cm (L × W × H) which is {{Convert|5000|cm2||abbr=on}}.<ref>Tierärztliche Vereinigung für Tierschutz e.V., [https://www.tierschutz-tvt.de/alle-merkblaetter-und-stellungnahmen/ Merkblatt Nr. 156 – Heimtiere: Goldhamster (Stand: 2014)], pets: golden hamster, Housing</ref>
A [[hamster wheel]] is a common type of environmental enrichment, and it is important that hamsters have a wheel in their cage. TVT recommends wheels should be at least 30 cm for Syrian hamsters, since smaller diameters lead to permanent spinal curvatures, especially in young animals. They also recommend a solid running surface because rungs or mesh can cause injury, or [[Bumblefoot (infection)|bumblefoot]].<ref>Tierärztliche Vereinigung für Tierschutz e.V., [https://www.tierschutz-tvt.de/alle-merkblaetter-und-stellungnahmen/ Merkblatt Nr. 62 – Heimtierhaltung, Tierschutzwidriges Zubehör (Stand: Jan. 2010)], II. Anti-animal welfare accessories for small mammals, 7. Wheels</ref> A hamster should be able to run on its wheel without arching its back. A hamster that has to run with an arched back can have back pain and spine problems. A variety of toys and cardboard tubes and boxes can help to provide enrichment, as they are energetic and need space to exercise.<ref>{{cite book |last1=Alderton |first1=David |title=Hamster |url=https://archive.org/details/hamster0000alde |url-access=registration |date=2002 |publisher=Collins |isbn=978-0-00-712282-0 }}{{page needed|date=September 2019}}</ref>
Most hamsters in American and British pet stores are Syrian hamsters. Originally, Syrian hamsters occurred in just one color – the natural wild agouti – but they have since developed a variety of color and pattern mutations, including cream, white, blonde, cinnamon, tortoiseshell, black, three different shades of gray, dominant spot, banded, and dilute. Selective breeding has also produced a variety of coat types such as long-haired, satin, and [[Rex mutation|rex]].{{citation needed|date=September 2019}}
== Breeding == {{main|Syrian hamster breeding}} [[File:Hamster with babies.jpg|thumb|A hamster mother emerging from a tube to see her two young, which are less than a week old]] The practice of [[selective breeding]] of golden hamsters requires an understanding of their care, knowledge about [[Syrian hamster variations|breed variations]], a plan for [[selective breeding]], scheduling of the female body cycle, and the ability to manage a colony of hamsters.
=== Breed variations ===
{{See also|Syrian hamster variations}} Often long-haired hamsters are referred to by their nickname "teddy bear". They are identical to short-haired Syrians except for the hair length and can be found in any color, pattern, or other coat type available in the species. Male long-haired hamsters usually have longer fur than the female, culminating in a "skirt" of longer fur around their backsides. Long-haired females have a much shorter coat although it is still significantly longer than that of a short-haired female.
{{Clear}}
== See also ==
* [[Turkish hamster]] * [[Romanian hamster]] * [[Hamster racing]] * [[Winter white dwarf hamster]] * [[Roborovski dwarf hamster]] * [[Campbell's dwarf hamster]] * [[Martin R. Ralph]] (for experiments done with golden hamsters and their circadian rhythms)
== References ==
{{Reflist}}
=== Sources ===
* {{cite book |last1=Valentine |first1=Helen |last2=Daugherity |first2=Erin K. |last3=Singh |first3=Bhupinder |last4=Maurer |first4=Kirk J. |editor1-last=Suckow |editor1-first=Mark A. |editor2-last=Stevens |editor2-first=Karla A. |editor3-last=Wilson |editor3-first=Ronald P. |title=The laboratory rabbit, guinea pig, hamster, and other rodents |date=2012 |publisher=Elsevier Academic Press |location=Amsterdam |isbn=978-0-12-380920-9 |pages=875–898 |edition=1st. |chapter=The Experimental Use of Syrian Hamsters}}
== External links ==
{{Commons}} * [http://www.humanesociety.org/animals/hamsters/ HSUS (Humane Society of the U.S.) Hamster care] * [https://web.archive.org/web/20090407054851/http://www.aspca.org/pet-care/small-pet-care/hamster-care.html ASPCA Hamster Information] * [https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&id=10036&lvl=3&keep=1&srchmode=1&unlock Genome information] {{Hamster}}
{{Taxonbar|from=Q204175}} {{Authority control}}
[[Category:Golden hamster]] [[Category:Mammals of the Middle East]] [[Category:Mammals described in 1839]] [[Category:Rodents as pets]] [[Category:Articles containing video clips]] [[Category:Taxa named by George Robert Waterhouse]]