Syrian Hamster

Conservation status
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Mammalia
Order: Rodentia
Suborder: Myomorpha
Superfamily: Muroidea
Family: Cricetidae
Subfamily: Cricetinae
Genus: Mesocricetus
Species: M. auratus
Binomial name
Mesocricetus auratus
Waterhouse, 1839
The Syrian Hamster or Golden Hamster, Mesocricetus auratus, is a very well-known member of the rodent subfamily Cricetinae, the hamsters. In the wild they are now considered vulnerable, due to farmers poisoning them,[1] but are popular as housepets and scientific research animals. Adults grow from 5 to 7 inches (13 to 18 cm) in length, and will usually have a lifespan of 2 to 3 years. They do not like direct sunlight. Although often considered nocturnal, Syrian hamsters display crepuscular behaviour, being most active at dusk and dawn.

Contents

Biology

Syrian hamster

Like most members of the subfamily, the Syrian Hamster has expandable cheek pouches, 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 dialect where they were found translates to "father of saddlebags" (Arabic: أبو جراب) due to the amount of storage space in their cheek pouches. If food is plentiful, they store it in large amounts—it has been reported that 25 kg of grain was found in the burrow of a single hamster.

Sable coloured Syrian hamster filling cheek pouches

Sexually mature female hamsters come into season (oestrus) every four days. Syrian hamsters have the shortest gestation period in any known placental mammal at only 16 to 18 days. They can produce large litters of 20 or more young, although the average litter size is between 8 to 10 pups. If a mother hamster is inexperienced or feels threatened, she may abandon or even eat her pups. A female hamster will come into season almost immediately after giving birth, and can become pregnant despite already having a litter. This puts a lot of stress on the mother's body and often results in very weak and undernourished young.

Hamsters are very territorial and may attack others. Exceptions do occur, usually when a female and male come together when the female is in heat, and even so the female may attack the male after mating. Even brothers and sisters, once mature, may attack one another. In captivity, babies should be separated from their mother and by gender after 4 weeks as they can often breed from 4–5 weeks old so care should be taken to prevent such close inbreeding, and the same-sex groups of babies can be housed together only for a further 3 weeks until they feel the need to establish territories.

Syrian hamsters mark their burrow with secretions from special scent glands on their hips. Male hamsters in particular lick their body near the glands, creating damp spots on the fur, then drag their sides along objects to mark their territory. Females will often use bodily secretions and feces.

Discovery

In 1839 British zoologist George Robert Waterhouse found an elderly female hamster in Syria, naming it Cricetus auratus, the "golden hamster".This type specimen's skin was stored at the British Museum (Natural History), but there was little scientific interest in the species for the next century.

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. Some escaped from the cage through a hole in the floor, and most of the wild Syrian hamsters in Israel today are believed to be descended from this litter.[2][3]

Descendants of the captive hamsters were shipped to Britain in 1931, where they came under the care of the Wellcome Bureau of Scientific Research. They bred well 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.[4]

A separate stock of hamsters was exported from Syria to the US in 1971, but it appears that none of today's North American pets are descended from these (at least in the female line), because recent mitochondrial DNA studies have established that all domestic golden hamsters are descended from one female – probably the one captured in 1930 in Syria.[5]

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 Syrian Hamster of Mesocricetus auratus.[6]

Surviving 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 Syrian hamster in northern Syria and southern Turkey, two expeditions were carried out during 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 Syrian hamsters, together with three wild individuals from the University of Aleppo, were shipped to Germany to form a new breeding stock.[7]

Observations of females in this wild population have revealed that contrary to laboratory populations, activity patterns are crepuscular rather than nocturnal, possibly to avoid nocturnal predators such as owls.[8]

Syrian hamsters in scientific research

Hamsters are widely used in research. For example, according to the Canadian Council for Animal Care, a total of 6,402 hamsters were used for research in 2006 in Canada, making them the fourth most popular rodent after mice (910,540), rats (331,560), and gerbils (37,246).[9]

In captivity, Syrian hamsters follow well defined daily routines of wheel-running activity, which has made them popular subjects in circadian rhythms research. They have a number of fixed action patterns that are readily observed, including scent-marking and body grooming, which is of interest in ethology (the study of animal behaviour).

But by far the greatest use of hamsters is in biomedical research. Among other things, because captive Syrian hamsters are highly inbred (being descended from only a few captured individuals) they have a high incidence of a genetic heart condition causing dilated cardiomyopathy. Several inbred strains of hamsters have been developed as animal models for human forms of dilated cardiomyopathy. The gene responsible for hamster cardiomyopathy in a widely studied inbred hamster strain, BIO14.6, has been identified as being delta-sarcoglycan.[10] Pet hamsters are also potentially prone to cardiomyopathy, which is a not infrequent cause of unexpected sudden death in adolescent or young adult hamsters.

Scientific studies of animal welfare concerning captive Syrian hamsters have shown that they prefer to use running wheels of large diameters, and that they prefer bedding material which allows them to build nests, if nesting material is not already available.[11]

Hamsters as pets

A pet Syrian hamster, banded Cream
Syrian Hamsters are popular as house pets due to their docile, inquisitive nature and small size however these animals have some special requirements that must be met in order for them to be happy and healthy. Although some people mistakenly think of them as a pet for young children, the American Society for the Prevention of Cruelty to Animals (ASPCA) recommends Hamsters as pets ONLY for persons 7 years or older and the child should be supervised by an adult.

Most hamsters in American and British pet stores are Syrian Hamsters. Originally, Syrian Hamsters came in just one color — the mixture of brown, black, and gold which gave them their "Golden" name — but they have since developed a myriad of color mutations such as cream, white, blonde, banded, tortoiseshell, calico, and sable. Therefore, in pet stores today, Golden Hamster is only used to label the original coloration (also known as agouti). Other-colored short-hairs are banded under the label Fancy Hamster.

The Humane Society of the United States (HSUS) states there is no such thing as a habitat that is too big for a hamster. The Hamster will spend the majority of their time in the cage, so it should be as big as possible, safe, comfortable and interesting. Syrian hamsters are energetic and need space to exercise.
A young Sable Banded Hamster explores a cardboard box

Most hamsters in American and British pet stores are Syrian Hamsters. Originally, Syrian Hamsters came in just one color — the mixture of brown, black, and gold which gave them their "Golden" name — but they have since developed a myriad of color mutations such as cream, white, blonde, banded, tortoiseshell, calico, and sable. Therefore, in pet stores today, Golden Hamster is only used to label the original coloration (also known as agouti). Other-colored short-hairs are banded under the label Fancy Hamster.

The Humane Society of the United States (HSUS) states there is no such thing as a habitat that is too big for a hamster. The Hamster will spend the majority of their time in the cage, so it should be as big as possible, safe, comfortable and interesting. Syrian hamsters are energetic and need space to exercise.

Long-haired or "Angora" hamsters

A male "Teddy Bear" hamster
"Angora" hamsters are commonly known as "Teddy Bear" hamsters. Female Teddy Bear hamsters have short velvety fur, that comes in many different colors. Male teddy bear hamsters usually have much longer fur than the female variety, culminating in a "skirt" of longer fur around their backsides.

Black Bears are a recent off-shoot of teddy bear hamsters (mutation discovered in 1985), the major difference being their black-colored fur. It can be argued[who?] that black bears are just black teddy bears rather than their own breed; on the other hand, black bears were originally selectively bred for their larger size and more docile nature as well as their color. However, in current stock, this is no longer the case.

See also

References

  1. ^ Yigit, N. & Kryštufek, B. (2008). Mesocricetus auratus. 2008 IUCN Red List of Threatened Species. IUCN 2008. Retrieved on 2 January 2008. Currently it qualifies for Vulnerable (VU B1ab(ii,iii,v))
  2. ^ Alderton, David. Rodents of the World, 1996, page 32. ISBN 0-8160-3229-7
  3. ^ :: Professor Paul's Lives of the Great Naturalists: Israel Aharoni
  4. ^ Alderton, D., 2002, Hamster: a practical guide to caring for your hamster, Harper Collins Publishers Ltd, London.
  5. ^ Bryan Sykes, The Seven Daughters of Eve: The Science That Reveals Our Genetic Ancestry, pages 58-62 ISBN 0393020185
  6. ^ Don E. Wilson & DeeAnn M. Reeder (editors). 2005. Mammal Species of the World. A Taxonomic and Geographic Reference (3rd ed), Johns Hopkins University Press. ISBN 1-800-537-5487: Mesocricetus
  7. ^ Letterman ET AL. 2001. Notes on the current distribution and the ecology of wild golden hamsters (Meretricious aural). Journal of Zoology, 254: 359-365 (Cambridge University Press). Online abstract
  8. ^ Letterman, R., Johnston, R.E., Legit, N., ET AL., 2008, Golden hamsters are nocturnal in captivity but diurnal in nature, Biology Letters 4: 253-255.
  9. ^ CCAC - Facts and Figures
  10. ^ Nigro V, Okazaki Y, Belsito A et al. Identification of the Syrian hamster cardiomyopathy gene. Human Molecular Genetics Vol. 6, 601-607, 1997. Link to abstract at [1]
  11. ^ Reebs, S.G., and St-Onge, P., 2005, Running wheel choice by Syrian hamsters, Laboratory Animals 39: 442-451; Lanteigne, M., and Reebs, S.G., 2006, Preference for bedding material in Syrian hamsters, Laboratory Animals 40: 410-418.

External links