Roborovski hamster

Roborovski hamster
Scientific classification
Kingdom:Animalia
Phylum:Chordata
Class:Mammalia
Order:Rodentia
Family:Cricetidae
Subfamily:Cricetinae
Genus:Phodopus
Species: P. roborovskii
Binomial name
Phodopus roborovskii
(Satunin, 1903)
Distribution of P. roborovskii

Roborovski hamster (Phodopus roborovskii; formerly Cricetulus bedfordiae), also known as desert hamster or Robo, is the smallest of three species of hamster in the genus Phodopus, averaging under 2 centimetres (0.8 in) at birth and 4.5–5 centimetres (1.8–2.0 in) and 20–25 grams (0.71–0.88 oz) during adulthood.[2] Distinguishing characteristics of the Roborovskis are eyebrow-like white spots and the lack of any dorsal stripe (found on the other members of the genus Phodopus). The average lifespan for the Roborovski hamster is three years, though this is dependent on living conditions (extremes being four years in captivity and two in the wild).[3] Roborovskis are known for their speed and have been said to run an equivalent of four human marathons each night on average.[4]

Distribution and habitat

Roborovski hamsters are found in desert regions, such as the basin of the lake Zaysan in Kazakhstan and regions of Tuva, Mongolia and Xinjiang in China.[5] The hamsters inhabit areas of loose sand and sparse vegetation and are rarely found in areas of dense vegetation and solid clay substrates.[6] They live at elevations of around 1,200 metres (3,900 ft)–1,450 metres (4,760 ft) and although research has been carried out, no fossil record exists for this species.[7][8] Their efficient use of water makes them particularly suited to the steppe and desert regions they inhabit. They dig and live in burrows with steep tunnels as deep as six feet underground. In the wild, Roborovski hamsters are crepuscular, being most active at dawn and dusk.

The Roborovski hamster has been found to be more common in the southern area of its distribution range, in areas such as Yulin, Shaanxi, China. It has been reported as a common sighting by locals in this city and in the sand dunes of the Ordos desert.[9]

Diet

They are omnivorous; they primarily eat grains, vegetables, fruit, and plants, but they will also eat meat and insects in small quantities. Roborovski hamsters remain underground in winter and survive in that season by stockpiling some food in warmer weather and storing it in special food chambers within their burrow system.

The Roborovski hamster mainly feeds on seeds. In Tuva it primarily lives on the seed of the sand alyssum, Nitre Bush, Siberian peashrub, Dracocephalum peregrinum, and milkvetch as well as sedges during the summer-months. Vegetative plant parts are not of significance.[6]

In the Chinese province of Shaanxi it is known for foraging millet seeds.[10]

In Mongolia, insects like beetles, earwigs and crickets are part of its diet. According to Formosow the stock of several burrows indicate an almost insect-based diet.[11] Also the consumption of snails has been reported.[12]

In Tuva, the share of animal food is marginal. Flint and Golowkin determined in 1958 and 1959 that nearly 100 percent of the cheek pouches' content consisted of plant food, whereas animal food was only found in 23 percent of the hamsters' pouches at all in 1958 and 32  percent in 1959.[13]

The daily dietary intake of the Roborovski hamsters heavily depends on its body weight. Juveniles have higher intakes of food compared to their weight than adult hamsters. Based on its population structure, Wan et al. calculated an average food intake of ca. two gram plant seeds per day. They specify the functional relation between the daily food intake (N) and the body-weight (M) to be [14]

Pups, juveniles as well as adult hamsters are foraging food in their burrows.[15]

History of human contact

Lt. Vsevolod Roborovski [Russian expeditioner] first made note of these hamsters, discovering them on an expedition in July 1894, though they were not studied scientifically for the best part of another decade, until Konstantin A. Satunin made observations in 1903.[16] The London Zoo imported them into the UK in the 1960s, but the first Roborovski hamsters studied in Britain were imported in the 1970s from Moscow Zoo. (None of them, however, bore offspring.)[17][18] Continental European countries had more success in breeding some Roborovskis, however, and those currently in the UK are descendants of a batch imported from the Netherlands in 1990. They were imported to the USA in 1998,[19] though they are now commonly found in pet shops in several countries. In South Korea, they are almost as common as the winter-white Russian dwarf hamster.

Variation

The Roborovski hamster is distinguished from the Djungarian hamster (Phodopus sungorus) and Campbell's dwarf hamster (Phodopus campbelli) due to its smaller size, sandy coloration of fur and its lack of a dorsal stripe.[20][21] When observed from behind, the neurocranium is rounded and does not appear to be as rectangular as Phodopus campbelli and Phodopus sungorus. The cusps of the lower molars are directly opposite and not alternate, as seen in other members of the genus, and the incisive foramen of the Roborovski hamster is greater than 4 millimetres (0.16 in) in length and is shorter than the length of the upper tooth row, which is uncharacteristic of the other two members of the genus.[20]

Currently, 10 variations of Roborovski hamsters are confirmed.[22][23]

  • agouti — a natural grayish-brown with white underside and "eyebrows" (white over eyes)
  • "white face" — a dominant mutation producing an agouti-coloured hamster with a white face
  • "husky" — a recessive mutation producing a white-faced hamster with a paler, more orangey coat than the agouti colour
  • "mottled" or "pied" — both dominant and recessive mutations have been identified, these hamsters have the agouti colouring with irregular patches of white over their heads, bodies and sometimes their faces
  • "platinum" — a combination of the dominant white face gene and the husky gene that produces a hamster that looks similar to a white-faced when young, but fades with age to nearly white
  • "head spot" — a combination of the dominant and recessive pied genes that creates a pure white animal with one patch of colour on the head
  • "white-from-white-faced" or "dark-eared white" — a combination of the dominant white-faced gene and the husky gene that produces a white hamster that retains a greyish undercoat and ears
  • "white-from-pied" or "pure white" — a combination of the two pied genes that produces a pure white hamster
  • "red-eyed" — a recessive mutation that produces a caramel-coloured hamster with a chocolate undercoat, dark brown (red) eyes, and pale ears

Breeding in captivity has also produced a darker dilution of the naturally sandy-coloured agouti fur. According to Fox (2006) white faced and derived breeds are considered torture-breeding and therefore breeding them is forbidden by law in several European countries like Germany or Austria. The homozygous carrier of the gene variant causes neurological symptoms similar to the whirling disease, where the animal spins itself around until it dies of exhaustion.[24][25]

Breeding

The gender of a Roborovski is determined visually; female openings are very close together and may even look like a single opening, while male openings are further apart. Males usually have a visible scent gland near the navel above the two openings, appearing as a yellow stain.

The breeding season for the Roborovski hamster is between April and September. The gestation period is between 20 and 22 days, producing three to four litters. The litter size is between three and nine, with an average of six.[6]

The offspring weigh 1 gram (0.035 oz)–2.1 grams (0.074 oz) at birth.[26][27] Upon being born, the offspring have no fur, the incisors and claws are visible, but the eyes, pinnae of the ear and digits are all sealed. After a period of three days, the whiskers become visible and after five days, the first dorsal hairs develop. The digits separate after six days and after eleven days, the body is completely formed. The young hamsters open their eyes by day 14

As pets

A group of young male Roborovski hamsters hiding in a small resin cave.
A Roborovski hamster in its enclosure.

Roborovski hamsters have become increasingly popular as pets in recent years, however, they are best suited to life as merely observational creatures, with limited interaction between them and humans, due to their increased activity levels that lead to a high stress predisposition and decreased ease of handling when compared to other domestic hamster species.[28] They are not recommended as pets for young children.[29]

On average, Roborovski hamsters will live 26 months (2 1/3 years) in captivity.[28]

Although claimed to be hypoallergenic, Roborovski hamsters have been associated with the development of asthma in previously asymptomatic owners.[30]

In rare emergency situations, a shallow dish of warm water may be necessary to clean harmful substances from a hamster's fur; however, under normal circumstances, hamsters should never be bathed in water as, aside from being incredibly stressful, this can remove vital protective oils from their coat, which can be very dangerous and potentially fatal.[31][32] Hamsters frequently groom themselves, and instead of water, a sand bath should be offered to help them stay clean and healthy (See 'Bedding/Substrate' subsection for more information).[33]

Housing

DIY cage example (Ikea Detolf - 157x38cm Approx. 0.6sq metres)

Unlike other species of hamster (see 'Golden hamster'), Roborovski hamsters can be kept in same-sex pairs or small groups if raised together from a young age.[34][35] A lone, or pair of Roborovski hamsters should be kept in a cage a minimum of 50 x 100 cm, or the equivalent of 0.5sq metres[36][37] with at least 15–20 cm of substrate, so that they may exercise their natural urge to burrow.[38][39] However, greater floor space and substrate depth is recommended for all species of hamsters, where "bigger is always better" .[37] Additional levels do not count toward the base area.[40] Aquariums and DIY-enclosures are commonly used amongst hamster enthusiasts, often preferred for their capability to hold greater amounts of substrate, wide availability, and cost, amongst various other reasons, over their more traditional wire-cage counterparts (See images for examples).[41]

If fighting within a group occurs, the hamsters should be separated immediately to avoid injury.

Example of a commonly used wire cage (Alaska - 80x50cm Approx 0.4sq metres)

Roborovski hamsters are very active, so a species-appropriate wheel is a necessity.[42] Size is still debated, however the general consensus is that a wheel should be no smaller than 16.5 cm (6.5 inches).[42] Other sources recommend a diameter of 20 cm(8 inches).[43]

Roborovski hamsters, like many rodents, will naturally avoid large open spaces, opting to stick close to the walls if forced to cross one, where they feel safest.[44] Providing them with multiple hiding spots is vital. This can be achieved by placing branches, tunnels and various other hides in close arrangement.

A good example of a Roborovski hamster enclosure, containing plenty of tunnels and hides.

Food

Based on their natural diet, owners should feed hamster food containing mainly grains and small seeds.[45][28] Animal protein should also be offered, in form of mealworms, grasshoppers or other insects. If you do not like to feed them alive, you can purchase dried insects. Some hamsters also accept seafood such as dried gammarus.[45]

To support their natural behaviour of foraging and stockpiling, feed should be scattered around the enclosure, hidden in several spots, or slightly buried beneath the substrate (Approximately 1tsp of food per hamster per day).[45]

Some unsuitable foods include:[46]

Fresh water should be available at all times. A bowl is preferable to a bottle, as it encourages a more natural and comfortable drinking posture.[45]

Hamsters' incisors never stop growing and they have a ‘self-sharpening’ system where the incisors grind against each other while gnawing, which wears the teeth down; so providing them with chew-toys is essential.[47]

Bedding/Substrate

Materials that separate into thin strands, e.g. cotton wool or similar 'fluffy' bedding products, pose a serious risk to the health and welfare of hamsters, due to the possibility of entanglement or ingestion.[48] Nesting material should be easily shredded and digestible, such as unscented toilet paper, moss, hay or leaves.[49]

Softwood shavings (such as pine or cedar) are also unsuitable as they contain harmful chemicals which can damage the respiratory system of hamsters.[50][51] Conversely, hardwood shavings such as aspen are perfectly safe to use.

To help mimic the Roborovski hamsters natural habitat, a large bowl of sand should be made available at all times. Chinchilla sand makes the best choice, but children's play sand may also be used. The sand must be dust-free.[39] Bird sand is not suitable, because it contains sharp elements such as shards of broken shell.[39] Dust bathing is a vital part of a hamster's daily routine and helps to keep their coat healthy and shiny by removing excess oils.[52] The sand can be kept clean by sieving or washing out with water and drying.

References

  1. ↑ Shar, S. & Lkhagvasuren, D. (2008). "Phodopus roborovski". IUCN Red List of Threatened Species. Version 2008. International Union for Conservation of Nature. Retrieved 14 July 2009. Database entry includes a brief justification of why this species is of least concern.
  2. ↑ Carol, Heather. "Roborovski Hamster". Southern Hamster Club. Retrieved 26 April 2013.
  3. ↑ Chen, Michael. "How Long Do Hamsters Live?". Pet Gear Planet. Retrieved 16 March 2017.
  4. ↑ Maxwell, Gavin (Director), Hill, Bernard (Narrator) (2008). Wild China (Television production). UK: BBC Natural History.
  5. ↑ Ma, Y; Wang F; Jin S; Li S. (1987). "Glires (rodents and lagomorphs) of northern Xinjiang and their zoogeographical distribution" (in Chinese). Science Press of Academia Sinica: 274.
  6. 1 2 3 Flint, Vladimir; Jewgenjewitsch (1966). Die Zwerghamster der paläarktischen Fauna (in German). vol. 366. Wittenberg/Lutherstadt, Ziemsen. p. 97. Retrieved 28 February 2015.
  7. ↑ Oldfield, Thomas (April 1908). "The Duke of Bedford's Zoological Exploration in Eastern Asia. - XI. On Mammals from the Provinces of Shan-si and Shen-si, Northern China". Proceedings of the Zoological Society of London. 78 (4): 963–983. doi:10.1111/j.1469-7998.1908.00963.x. Retrieved 25 January 2014.
  8. ↑ Topál, GY. (1973). O.G, Dely, ed. "Zur Säugetier-Fauna der Mongolei. Ergebnisse der zoologischen Forschungen von Dr. Z. Kaszab in der Mongolei. Nr. 322" [On the mammalian fauna of Mongolia. Results of the zoological research of Dr. Z. Kaszab in Mongolia. # 322] (PDF). Vertebrata hungarica Musei historico-naturalis hungarici (in German). Népművelési Propaganda Iroda, Budapest. 14: 47–100. ISSN 0506-7839. Retrieved 25 January 2014.
  9. ↑ Sowerby, Arthur de Clare (1914). Fur and feather in North China. University of California Libraries: Tientsin Press. p. 68. Retrieved 1 March 2015.
  10. ↑ Allen, 1940; Thomas, 1908. Cited in: Ross, 1994 ("Ecology" p. 3).
  11. ↑ Alexander Nikolajewitsch Formosow (1929). [The Mammals of northern Mongolia of the Sboram-expedition 1926] Млекопитающие Северной Монголии по сборам экспедиции 1926 г. In: Предварительный отчет Зоологической экспедиции в Северную Монголию. [Preliminary Report of the zoological expedition into northern Mongolia] (in Russian). Sankt Petersburg: publisher of the Sovjet Academy of Science. pp. 1–144. cited in: Ross, 1994 ("Ecology" p. 3).
  12. ↑ Zdenêk Veselovský; S. Grundová (1964). "Beitrag zur Kenntnis des Dschungar-Hamsters, Phodopus sungorus". 30. Pallas: 305–311. ISSN 0044-3468. cited in: Ross, 1994 ("Ecology" p. 3).
  13. ↑ Flint und Golowkin, 1961. cited in: Flint, 1966 ("Diet" p. 36).
  14. ↑ Wan Xin-Rong; Liu Wei; Wang Guang-He; Zhong Wen-Qin (2007). [Food Consumption and Feeding Characters of Phodopus roborovskii on Hunshandake sandy land of Inner Mongolia]. [Chinese Journal of Ecology] (in Chinese). vol. 26. pp. 223–227. ISSN 1000-4890.
  15. ↑ Boris Stepanowitsch Judin; Lijana Iwanowa Galkina; Antonina Fedorowna Potapkina (1979). [Mammals of the Altai-Sayan Mountain Region] Млекопитающие Алтае-Саянской горной страны. Nowosibirsk: Nauka. p. 296. cited in: Ross, 1994 ("Ecology" p. 3)
  16. ↑ DwarfHamsters- Judith Lissenberg p.22-23
  17. ↑ Konijnen en Knaagdieren Encyclopedie - Esther Verhoeff-Verhallen p.130-131
  18. ↑ Petwebsite.com
  19. ↑ Website specifically about Roborovski hamsters
  20. 1 2 Argyropulo, A.I (1933). "Die Gattungen und Arten der Hamster (Cricetinae Murray, 1866) der Paläarctic". Zeitschrift für Säugetierkunde (in German). 20: 129–149.
  21. ↑ Vorontsov, N.N (1960). "Species of Palaearctic hamsters (Cricetinae, Rodentia) in statu nascendi". Doklady Biological Sciences. 132: 491–493.
  22. ↑ Oak Farm Roborovskis
  23. ↑ My New Robos - 'Head Spot' and 'Pure White'
  24. ↑ Judy Fox (2006). Mein Zwerghamster zu Hause (in German) (4th ed.). Ruhmannsfelden: Bede-Verlag. p. 64. ISBN 3-89860-121-8. p. 11, p. 50
  25. ↑ Patricia D. Ross (1994). Phodopus roborovskii (PDF). Mammalian Species. pp. 1–4. ISSN 0076-3519.
  26. ↑ Flint, WJ; Golovkin, N (1961). "A comparative study of hamster ecology in the Tuva area". Byulletin Moskovskogo Obshchestva Ispytaelei Priody Otdel Biologichskii (in Russian): 57–76.
  27. ↑ Yudin, BS; Galkina, LI; Potapkina, AF (1979). "Mammals of the Altai-Sayanskoi Gorni district" (in Russian). Nauka: 296.
  28. 1 2 3 "Phodopus roborovskii (desert hamster)". Animal Diversity Web. Retrieved 2018-02-21.
  29. ↑ "Robo Dwarf Hamsters". Dwarf Hamster Home. Retrieved 2018-02-22.
  30. ↑ Niitsuma et al., J. Invest. Allergol. Clin. Immunol. 2004; 14(3):221-224
  31. ↑ "All about hamster grooming | The Hamster House". The Hamster House. 2015-02-14. Retrieved 2018-02-22.
  32. ↑ "Bathing Hamsters (Don't do it!)". thepipsqueakery.org. Retrieved 2018-02-22.
  33. ↑ "How to Bathe a Hamster - Dwarf Hamster Blog". Dwarf Hamster Blog. 2014-04-22. Retrieved 2018-02-22.
  34. ↑ "Robo Dwarf Hamster - All About Roborovski Dwarf Hamsters". Dwarf Hamster Blog. 2013-03-04. Retrieved 2018-02-22.
  35. ↑ "http://www.oakfarmrabbitsandrodents.co.uk/robo/main.html". www.oakfarmrabbitsandrodents.co.uk. Retrieved 2018-02-22. External link in |title= (help)
  36. ↑ "Cage size". www.tierschutzverein-kirchheim.de. Retrieved 2018-02-21.
  37. 1 2 "Wissenschaftliche Fakten wie ein Hamsterheim beschaffen sein sollte". hamstergehege.blogspot.co.uk. Retrieved 2018-02-21.
  38. ↑ "Wissenschaftliche Fakten wie ein Hamstergehege beschaffen sein sollte - Gehegevorstellung - www.das-hamsterforum.de". www.das-hamsterforum.de (in German). Retrieved 2018-02-21.
  39. 1 2 3 "Zubehör". hamster-info-net.blogspot.co.uk. Retrieved 2018-02-21.
  40. ↑ "Gehege". hamster-info-net.blogspot.co.uk. Retrieved 2018-02-21.
  41. ↑ "Types of Hamster Cages and Their Pros and Cons". Dwarf Hamster Blog. 2013-03-12. Retrieved 2018-02-22.
  42. 1 2 "Why your hamster needs a wheel". The Hamster House. 2014-10-02. Retrieved 2018-02-21.
  43. ↑ "Wheel size". hamster-info-net.blogspot.co.uk. Retrieved 2018-02-21.
  44. ↑ "Open Field (animal test) - an overview | ScienceDirect Topics". www.sciencedirect.com. Retrieved 2018-02-23.
  45. 1 2 3 4 "Einführung in die Ernährung und Futterliste - Futter und Ernährung - www.das-hamsterforum.de". www.das-hamsterforum.de (in German). Retrieved 2018-02-21.
  46. ↑ "What Can Hamsters Eat? Carrots, Grapes, Tomatoes, and More | petMD". www.petmd.com. Retrieved 2018-02-22.
  47. ↑ "Hamster care - everything you need to know | RSPCA". Retrieved 2018-02-22.
  48. ↑ "A suitable environment for hamsters - RSPCA". Retrieved 2018-02-22.
  49. ↑ "Nesting material". hamster-info-net.blogspot.co.uk. Retrieved 2018-02-21.
  50. ↑ "What is the Best Hamster Bedding? - Dwarf Hamster Blog". Dwarf Hamster Blog. 2013-06-26. Retrieved 2018-02-22.
  51. ↑ "Hamster Bedding: The Best Options | The Hamster House". The Hamster House. 2014-10-02. Retrieved 2018-02-22.
  52. ↑ Flint, 1966 ("Biotopes" p. 20–21).

Further reading

  • Lissenberg, J. Dwerghamsters. Aanschaf, verzorging, Voeding, Fokken Zuidboek Producties: Lisse, The Netherlands: 2002
  • Verhoeff-Verhallen, E. Konijnen en Knaagdieren Encyclopedie Rebo Productions: Lisse, The Netherlands: 1997
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