Editing Winter white dwarf hamster (section)

==Physical description==
[[File:Winter white hamster agouti2.jpg|left|thumb|98x98px|Agouti colouration (natural color)]]
[[File:Winter white hamster pearl.jpg|left|thumb|95x95px|Pearl colouration]]
[[File:Winter white hamster sapphire.jpg|left|thumb|95x95px|Sapphire colouration]]
[[File:Winter white hamster pearl sapphire.jpg|left|thumb|95x95px|Pearl sapphire colouration]]
[[File:Winter white hamster merle.jpg|left|thumb|95x95px|Merle colouration]]
[[File:Winter white hamster merle sapphire.jpg|left|thumb|95x95px|Merle sapphire colouration]]
The coat of the winter white dwarf hamster is less woolly than that of [[Campbell's dwarf hamster]],<ref name="aboutpets book">The Dwarf Hamster: A Guide to Selection, Housing, Care, Nutrition, Behaviour, Health, Breeding, Species and Colours (About Pets) {{ISBN|978-1-85279-210-7}}</ref> and apart from the normal colouring, they can be coloured sapphire, sapphire pearl, or normal pearl. The head and body length of the winter white dwarf hamster is 70–90&nbsp;mm, the length of the tail is 5–15&nbsp;mm, and the hind legs are 11–15&nbsp;mm.<ref name="WA1941:R1998:GC">Winogradow und Argiropulo 1941. Zitiert in: Ross 1998 (S.&nbsp;1, „General Characters“)</ref><ref name="KS1964:R1998:GC">Krylzow und Schubin 1964. Zitiert in: Ross 1998 (S.&nbsp;1, „General Characters“).</ref> The [[body weight]] changes dramatically throughout the year. It is at its lowest during the winter.<ref name="Bartness1985">Bartness & Wade, 1985. Photoperiodic control of seasonal body weight cycles in hamsters (Abstract)</ref> In males, the body weight ranges from {{convert|19|to|45|g|oz}}, and in females, {{convert|19|to|36|g|oz}}.<ref name="KS1964:R1998:GC"/> In human care, they are slightly heavier. The average lifespan of the winter white dwarf hamster is one to three years in [[Captivity (animal)|captivity]], though they can live longer. In the wild, they are known to live as little as one year.<ref name="aboutpets book" />

In summer, the fur of the winter white hamster on the back changes from ash-grey to dark brown, or sometimes pale brown with a [[tint]].<ref name="How2care">How to Care for Your Dwarf Hamster (Your first...series) {{ISBN|1-85279-150-0}}</ref> The face changes to grey or brown, while the mouth area, the [[whisker]] area, and the ears are slightly brighter.<ref name="F1973">Figala und Mitarbeiter 1973 (Abstract). Die Angaben beziehen sich auf unter natürlichen Bedingungen gehaltene Hamster.</ref> The outer ears and the eyes have black edges. The rest of the head is dark brown or black. From the head to the tail runs a black-brown dorsal stripe.<ref name="R1992:R1998">
{{cite book
  | last = Ross
  | first = Patricia
  | author-link = Patricia Ross
  | title = On activity and behavior of three taxa of dwarf hamsters of the genus ''Phodopus'' Miller, 1910
  | series = Plant Journal of Mammalogy
  | pages = 65–76 
  | year = 1992
}}
Dissertation Quoted in Ross 1998 (p. 1, Diagnosis, General Characters "</ref> The throat, belly, tail and limbs are white.<ref name="F1973" /> The ears are grey with a pinkish tint<ref name="How2care" /> with scattered black hairs. The hairs on the underside are completely white.<ref name="L2002:158">
{{cite book
  | last = Hamann
  | first = U.
  | author-link = David Mumford
  | title = The Red Book of Varieties and Schemes
  | series = Lecture notes in mathematics 1358
  | year = 1987}} Quoted in Ross, 1998 (p. 1, "Context and Content" of the genre, "Diagnosis "</ref><ref>{{cite book
  | last = Logsdail
  | first = Chris
  | title = Hamsterlopaedia. A Complete Guide to Hamster Care
  | publisher = Ringpress Books
  | page = 174
  | year = 2005
  | isbn = 1-86054-246-8
}}</ref>
The bright coat the bottom extends to the shoulders, flanks, and hips in three arches upward. It is distinguished from the darker fur on the top of the existing black-brown hair, three curved line.<ref name="KS1964:R1998:GC" />

Apart from the typical colouration, winter white dwarf hamsters can also be coloured pearl, sapphire, sapphire pearl, and marbled. Other colorations are available, but these are strongly suspected to appear only in hybrid crossings with Campbell's dwarf hamsters. Some of these colorations are mandarin, blue, argente, yellow blue fawn, camel, brown, cream, merle, and umbrous.<ref name="aboutpets book" />

In the winter, the fur is more [[Density|dense]].<ref>{{cite book
  | last = Honey
  | first = Sandra
  | author-link = David Mumford
  | title = Dwarf hamsters. Biology. Attitude. Breeding 
  | publisher = Nature-and animal-Verlag
  | series = 2nd
  | year = 2005
  | pages = 9, 56–58
}}</ref>
They sometimes have a grey tint on their heads.<ref>Pallas 1773rd Quoted in Ross 1998 (p. 1, General Characters ").</ref>
More than 10% of the hamsters kept in the first winter develop the summer coat. In the second winter, only a few change into the winter coat and winter colour is less pronounced. The [[moulting]] in the winter fur starts in October or November and is completed in December, while the summer coat begins in January or February and is completed in March or early April.<ref name="F1973" /> The ears are grey with a pinkish tint.<ref name="aboutpets book" />
Moulting both run jobs on the head and the back of the spine to the sides, the legs and the underside.<ref>{{cite book
  | last = Zdenek
  | first = Veselovský
  | title = Contribution to knowledge of Dzungars-Hamsters, ''Phodopus sungorus'' (Pallas, 1773)
  | series = Journal of Mammalogy
  | year = 1964
  | pages = 305–311}}  Quoted in Ross 1998 (p. 1-2, " form ")</ref> The hairs grow longer in the summer, to about ten millimetres long.<ref name="How2care" />

The [[pigmentation]] of hair is controlled by the hormone [[prolactin]] and colour [[genetics]].<ref>{{cite journal
  | last =  Duncan
  | first = Marilyn
  | author-link = David Mumford
  | title =  Hormonal regulation of the annual pelage color cycle in the Djungarian hamster, ''Phodopus sungorus''. I. Role of the gonads and the pituitary
  | journal = The Journal of Experimental Zoology
 | publisher = Anthology The Journal of Experimental Zoology
  | year = 1984
  | volume = 230
 | issue = 1
 | pages = 89–95
| doi = 10.1002/jez.1402300112
 | pmid = 6726149
 }}</ref>
Day length can be less than 14 hours to initiate the change to winter coat, though it is possible they may be able to sense a directional change in photoperiod length, such as in one experiment that demonstrated a transition from 16 hours of light to 14 hours initiates a change to the winter coat.<ref>Niklowitz P., Lerchi A., Nieschlag, E. 1994. Photoperiodic responses in Djungarian Hamsters (Phodopus sungorus): Importance of Light History for Pineal and Serum Melatonin Profiles. Biology of Reproduction. 51: 714-724.</ref> The change to the winter coat can be triggered in the summer by the short day lengths. The change occurs back to the summer coat in the autumn, when the length of the days change again. At internal temperatures hamsters in captivity start later with the changes. The winter colour is less pronounced in them.<ref name="F1973" /> The eyes of the winter white hamster are black, unless it is [[albino]], in which case they are red.<ref name="How2care" />